APIM Moderation

Jeong Eun Cheon


Preparing for the analysis

Read in data

library(base)
Study3 <- read.csv("Study3_dyadic_dataset_anonymized.csv", sep = ";")

We aim to replicate the results of Study 3 from Czarna et al. (2022). Study 3 involves dyadic data where they tested a moderated Actor-Partner Interdependence Model (APIM).

The authors have provided access to their datasets and scripts via the Open Science Framework (OSF). You can access these materials at the following link: https://osf.io/8j4td/?view_only=dee38744aef04831b98484076616d98d.

We will use their provided codes as a basis to reconstruct and validate their core findings.

Reference: Czarna, A. Z., Śmieja, M., Wider, M., Dufner, M., & Sedikides, C. (2022). Narcissism and partner-enhancement at different relationship stages. Journal of Research in Personality, 98, 104212. https://doi.org/10.1016/j.jrp.2022.104212

Study 3

library(dplyr)

names(Study3)
##  [1] "Timef"                 "Codef"                 "Agef"                 
##  [4] "Plecf"                 "Sexf"                  "Orientationf"         
##  [7] "Monthsf"               "Selfesteemf"           "NPIf"                 
## [10] "Kto1f"                 "Kto2f"                 "Kto3f"                
## [13] "Kto4f"                 "Kto5f"                 "Kto6f"                
## [16] "Kto7f"                 "Kto8f"                 "Kto9f"                
## [19] "Kto10f"                "Kto11f"                "Kto12f"               
## [22] "Kto13f"                "Kto14f"                "Kto15f"               
## [25] "Partner_enhancement_f" "Timem"                 "Codem"                
## [28] "Agem"                  "Plecm"                 "Sexm"                 
## [31] "Orientationm"          "Monthsm"               "Selfesteemm"          
## [34] "NPIm"                  "Kto1m"                 "Kto2m"                
## [37] "Kto3m"                 "Kto4m"                 "Kto5m"                
## [40] "Kto6m"                 "Kto7m"                 "Kto8m"                
## [43] "Kto9m"                 "Kto10m"                "Kto11m"               
## [46] "Kto12m"                "Kto13m"                "Kto14m"               
## [49] "Kto15m"                "Partner_enhancement_m"
glimpse(Study3)
## Rows: 84
## Columns: 50
## $ Timef                 <chr> "43620,91287", "43627,74419", "43638,70676", "43…
## $ Codef                 <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1…
## $ Agef                  <int> 23, 23, 24, 24, 24, 24, 27, 22, 22, 22, 24, 25, …
## $ Plecf                 <chr> "Kobieta", "Kobieta", "Kobieta", "Kobieta", "Kob…
## $ Sexf                  <int> 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, …
## $ Orientationf          <chr> "hetero", "hetero", "hetero", "hetero", "hetero"…
## $ Monthsf               <int> 12, 24, 54, 72, 78, 24, 78, 54, 12, 48, 24, 84, …
## $ Selfesteemf           <int> 4, 6, 1, 5, 3, 5, 3, 6, 4, 3, 6, 3, 3, 5, 6, 5, …
## $ NPIf                  <chr> "3", "4,153846154", "3,076923077", "5", "2,69230…
## $ Kto1f                 <int> 4, 5, 9, 5, 2, 7, 4, 4, 6, 5, 6, 5, 2, 6, 4, 5, …
## $ Kto2f                 <int> 8, 7, 9, 5, 7, 4, 9, 8, 7, 8, 7, 5, 6, 8, 5, 5, …
## $ Kto3f                 <int> 5, 5, 7, 6, 5, 8, 5, 8, 7, 7, 8, 5, 2, 5, 6, 2, …
## $ Kto4f                 <int> 5, 5, 9, 7, 3, 5, 3, 5, 7, 6, 8, 5, 2, 6, 5, 4, …
## $ Kto5f                 <int> 7, 5, 5, 7, 7, 8, 3, 2, 7, 5, 9, 8, 2, 6, 7, 2, …
## $ Kto6f                 <int> 7, 5, 1, 4, 1, 2, 5, 5, 5, 5, 3, 4, 7, 5, 5, 9, …
## $ Kto7f                 <int> 5, 5, 5, 4, 4, 5, 5, 7, 6, 6, 7, 2, 7, 7, 5, 5, …
## $ Kto8f                 <int> 5, 6, 1, 5, 6, 2, 7, 6, 8, 5, 3, 5, 5, 3, 6, 8, …
## $ Kto9f                 <int> 5, 6, 1, 5, 2, 3, 8, 6, 5, 5, 5, 3, 5, 5, 4, 4, …
## $ Kto10f                <int> 5, 5, 1, 5, 7, 2, 8, 5, 8, 8, 5, 5, 4, 5, 5, 7, …
## $ Kto11f                <int> 2, 8, 9, 5, 9, 6, 1, 5, 4, 6, 8, 5, 3, 6, 9, 6, …
## $ Kto12f                <int> 2, 6, 1, 9, 5, 3, 9, 7, 5, 5, 8, 2, 4, 4, 7, 1, …
## $ Kto13f                <int> 4, 6, 1, 1, 9, 6, 1, 5, 3, 6, 8, 5, 7, 7, 7, 1, …
## $ Kto14f                <int> 2, 6, 5, 7, 1, 5, 1, 7, 5, 5, 8, 4, 7, 6, 5, 1, …
## $ Kto15f                <int> 3, 5, 1, 7, 5, 2, 1, 5, 5, 3, 8, 3, 5, 4, 5, 4, …
## $ Partner_enhancement_f <chr> "4,6", "5,666666667", "4,333333333", "5,46666666…
## $ Timem                 <chr> "43620,90824", "43627,47656", "43638,72503", "43…
## $ Codem                 <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1…
## $ Agem                  <int> 24, 26, 27, 25, 23, 26, 27, 24, 22, 23, 26, 24, …
## $ Plecm                 <chr> "M\xc7\xf9czyzna", "M\xc7\xf9czyzna", "M\xc7\xf9…
## $ Sexm                  <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, …
## $ Orientationm          <chr> "hetero", "hetero", "hetero", "hetero", "hetero"…
## $ Monthsm               <int> 12, 24, 54, 72, 78, 24, 78, 54, 12, 48, 24, 84, …
## $ Selfesteemm           <int> 5, 4, 5, 4, 4, 6, 5, 4, 6, 1, 5, 5, 5, 5, 6, 6, …
## $ NPIm                  <chr> "4,384615385", "3,076923077", "2,846153846", "3,…
## $ Kto1m                 <int> 5, 5, 3, 5, 5, 5, 3, 1, 6, 4, 6, 5, 4, 5, 7, 5, …
## $ Kto2m                 <int> 3, 3, 1, 5, 3, 4, 2, 1, 8, 1, 3, 2, 2, 2, 3, 5, …
## $ Kto3m                 <int> 3, 2, 3, 5, 3, 5, 3, 1, 6, 4, 4, 5, 6, 4, 5, 8, …
## $ Kto4m                 <int> 4, 5, 1, 5, 6, 5, 2, 1, 2, 5, 5, 3, 5, 3, 5, 5, …
## $ Kto5m                 <int> 3, 6, 5, 5, 6, 6, 7, 5, 2, 5, 3, 5, 6, 5, 4, 8, …
## $ Kto6m                 <int> 4, 5, 6, 5, 7, 6, 3, 5, 1, 5, 6, 5, 8, 3, 5, 3, …
## $ Kto7m                 <int> 5, 7, 3, 5, 8, 5, 5, 5, 1, 5, 5, 5, 5, 5, 5, 5, …
## $ Kto8m                 <int> 4, 5, 6, 5, 8, 8, 5, 5, 2, 5, 6, 5, 5, 5, 4, 4, …
## $ Kto9m                 <int> 1, 4, 6, 5, 8, 8, 5, 5, 2, 5, 5, 5, 7, 4, 7, 4, …
## $ Kto10m                <int> 5, 7, 7, 5, 7, 9, 4, 5, 1, 3, 5, 5, 7, 2, 5, 4, …
## $ Kto11m                <int> 5, 1, 1, 6, 4, 4, 7, 5, 8, 4, 3, 5, 5, 5, 1, 4, …
## $ Kto12m                <int> 5, 2, 4, 5, 5, 5, 5, 3, 9, 7, 3, 4, 6, 5, 2, 6, …
## $ Kto13m                <int> 5, 2, 6, 5, 4, 3, 5, 5, 9, 5, 3, 5, 4, 5, 5, 8, …
## $ Kto14m                <int> 5, 5, 3, 5, 6, 6, 5, 1, 6, 5, 4, 5, 4, 5, 5, 8, …
## $ Kto15m                <int> 5, 5, 6, 5, 7, 4, 7, 5, 7, 8, 4, 5, 5, 5, 3, 7, …
## $ Partner_enhancement_m <chr> "4,133333333", "4,266666667", "4,066666667", "5,…

Standardizing and manipulating variables

Create a standardized score based on the combined sample of males and females.

Study3$Partner_enhancement_m <- as.numeric(gsub(",", ".", Study3$Partner_enhancement_m))
Study3$Partner_enhancement_f <- as.numeric(gsub(",", ".", Study3$Partner_enhancement_f))
Study3$NPIf <- as.numeric(gsub(",", ".", Study3$NPIf))
Study3$NPIm <- as.numeric(gsub(",", ".", Study3$NPIm))

all_NPI_scores <- c(Study3$NPIf, Study3$NPIm)
mean_NPI <- mean(all_NPI_scores, na.rm = TRUE)
sd_NPI <- sd(all_NPI_scores, na.rm = TRUE)
Study3$zNPIf<- (Study3$NPIf - mean_NPI) / sd_NPI
Study3$zNPIm <- (Study3$NPIm - mean_NPI) / sd_NPI

all_months <- c(Study3$Monthsf, Study3$Monthsm)
mean_months <- mean(all_months, na.rm = TRUE)
sd_months <- sd(all_months, na.rm = TRUE)
Study3$zMonthsf<- (Study3$Monthsf - mean_months) / sd_months

#creating interactive variables
Study3$RLXNPIf <- Study3$zMonthsf*Study3$zNPIf
Study3$RLXNPIm <- Study3$zMonthsf*Study3$zNPIm

Model specification

Saturated model

library(lavaan)

#saturated model (fully unrestricted)
Model_unrestricted<- '
Partner_enhancement_f ~ zNPIf + zNPIm + zMonthsf + RLXNPIf + RLXNPIm
Partner_enhancement_m ~ zNPIm + zNPIf + zMonthsf + RLXNPIm +RLXNPIf
'
results_Model_unrestricted<- sem(Model_unrestricted, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model_unrestricted, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 8 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf                    0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm                   -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf                -0.039    0.088   -0.449    0.654   -0.039   -0.044
##     RLXNPIf                 -0.177    0.102   -1.733    0.083   -0.177   -0.170
##     RLXNPIm                  0.195    0.078    2.494    0.013    0.195    0.246
##   Partner_enhancement_m ~                                                      
##     zNPIm                    0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf                   -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf                 0.342    0.078    4.392    0.000    0.342    0.394
##     RLXNPIm                 -0.137    0.069   -1.972    0.049   -0.137   -0.177
##     RLXNPIf                 -0.151    0.091   -1.662    0.097   -0.151   -0.148
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf ~~                                                             
##     zNPIm                     0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.060
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.072
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.081
##     RLXNPIm                   0.007    0.120    0.060    0.952    0.007
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478    0.066
##     RLXNPIm                   0.183    0.123    1.489    0.136    0.183
##   RLXNPIf ~~                                                           
##     RLXNPIm                   0.124    0.104    1.197    0.231    0.124
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##    -0.070
##    -0.064
##          
##    -0.093
##    -0.096
##     0.007
##          
##     0.078
##     0.165
##          
##     0.132
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.260    0.087   60.720    0.000    5.260    5.956
##    .Prtnr_nhncmnt_    4.456    0.077   57.955    0.000    4.456    5.160
##     zNPIf             0.038    0.110    0.342    0.732    0.038    0.037
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.038   -0.038
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.136   -0.161
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf             1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm             0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf           0.717    0.111    6.481    0.000    0.717    1.000
##     RLXNPIm           1.242    0.192    6.481    0.000    1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356
fitMeasures(results_Model_unrestricted, "df")
## df 
##  0

Simple slopes

Narcissism as the moderator:

#Testing simple slopes (for low and high narcissism)

#Low narcissism - men
Study3$zNPIm_low <- (Study3$zNPIm + 1)
Study3$RLXNPIm_low <- Study3$zMonthsf*Study3$zNPIm_low

Model3_lowm<- '
Partner_enhancement_f ~ zNPIf+ zNPIm_low + zMonthsf + a2*RLXNPIf + RLXNPIm_low
Partner_enhancement_m ~ zNPIm_low + zNPIf + zMonthsf + RLXNPIm_low + RLXNPIf
'
results_Model3_lowm<- sem(Model3_lowm, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model3_lowm, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 14 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf                    0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm_low               -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf                -0.234    0.126   -1.859    0.063   -0.234   -0.265
##     RLXNPIf   (a2)          -0.177    0.102   -1.733    0.083   -0.177   -0.170
##     RLXNPIm_l                0.195    0.078    2.494    0.013    0.195    0.356
##   Partner_enhancement_m ~                                                      
##     zNPIm_low                0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf                   -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf                 0.479    0.112    4.277    0.000    0.479    0.552
##     RLXNPIm_l               -0.137    0.069   -1.972    0.049   -0.137   -0.256
##     RLXNPIf                 -0.151    0.091   -1.662    0.097   -0.151   -0.148
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf ~~                                                             
##     zNPIm_low                 0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.060
##     RLXNPIm_low              -0.208    0.179   -1.165    0.244   -0.208
##   zNPIm_low ~~                                                         
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.081
##     RLXNPIm_low              -0.084    0.174   -0.485    0.627   -0.084
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478    0.066
##     RLXNPIm_low               1.177    0.217    5.413    0.000    1.177
##   RLXNPIf ~~                                                           
##     RLXNPIm_low               0.190    0.150    1.262    0.207    0.190
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##    -0.070
##    -0.128
##          
##    -0.093
##    -0.096
##    -0.053
##          
##     0.078
##     0.732
##          
##     0.139
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.581    0.121   46.274    0.000    5.581    6.321
##    .Prtnr_nhncmnt_    4.078    0.107   38.090    0.000    4.078    4.722
##     zNPIf             0.038    0.110    0.342    0.732    0.038    0.037
##     zNPIm_low         0.962    0.108    8.949    0.000    0.962    0.976
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.136   -0.161
##     RLXNPIm_low      -0.092    0.176   -0.521    0.602   -0.092   -0.057
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf             1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm_low         0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf           0.717    0.111    6.481    0.000    0.717    1.000
##     RLXNPIm_low       2.602    0.401    6.481    0.000    2.602    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356
#High narcissism - men
Study3$zNPIm_high <- (Study3$zNPIm - 1)
Study3$RLXNPIm_high <- Study3$zMonthsf*Study3$zNPIm_high

Model3_highm<- '
Partner_enhancement_f ~ zNPIf + zNPIm_high + zMonthsf + RLXNPIf + RLXNPIm_high
Partner_enhancement_m ~ zNPIm_high + zNPIf + zMonthsf + RLXNPIm_high + RLXNPIf
'
results_Model3_highm<- sem(Model3_highm, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model3_highm, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 17 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf                    0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm_high              -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf                 0.156    0.108    1.440    0.150    0.156    0.176
##     RLXNPIf                 -0.177    0.102   -1.733    0.083   -0.177   -0.170
##     RLXNPIm_high             0.195    0.078    2.494    0.013    0.195    0.302
##   Partner_enhancement_m ~                                                      
##     zNPIm_high               0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf                   -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf                 0.205    0.096    2.133    0.033    0.205    0.236
##     RLXNPIm_high            -0.137    0.069   -1.972    0.049   -0.137   -0.217
##     RLXNPIf                 -0.151    0.091   -1.662    0.097   -0.151   -0.148
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf ~~                                                             
##     zNPIm_high                0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.060
##     RLXNPIm_high              0.064    0.150    0.426    0.670    0.064
##   zNPIm_high ~~                                                        
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.081
##     RLXNPIm_high              0.099    0.147    0.670    0.503    0.099
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478    0.066
##     RLXNPIm_high             -0.811    0.173   -4.686    0.000   -0.811
##   RLXNPIf ~~                                                           
##     RLXNPIm_high              0.059    0.127    0.464    0.643    0.059
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##    -0.070
##     0.047
##          
##    -0.093
##    -0.096
##     0.073
##          
##     0.078
##    -0.595
##          
##     0.051
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    4.938    0.128   38.705    0.000    4.938    5.592
##    .Prtnr_nhncmnt_    4.834    0.113   42.688    0.000    4.834    5.597
##     zNPIf             0.038    0.110    0.342    0.732    0.038    0.037
##     zNPIm_high       -1.038    0.108   -9.649    0.000   -1.038   -1.053
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.136   -0.161
##     RLXNPIm_high     -0.091    0.149   -0.612    0.541   -0.091   -0.067
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf             1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm_high        0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf           0.717    0.111    6.481    0.000    0.717    1.000
##     RLXNPIm_high      1.870    0.289    6.481    0.000    1.870    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356
#Low narcissism - women
Study3$zNPIf_low <- (Study3$zNPIf + 1)
Study3$RLXNPIf_low <- Study3$zMonthsf*Study3$zNPIf_low

Model3_loww<- '
Partner_enhancement_f ~ zNPIf_low + zNPIm + zMonthsf + RLXNPIf_low + RLXNPIm
Partner_enhancement_m ~ zNPIm + zNPIf_low + zMonthsf + RLXNPIm + RLXNPIf_low
'
results_Model3_loww<- sem(Model3_loww, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model3_loww, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 14 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf_low                0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm                   -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf                 0.138    0.137    1.002    0.316    0.138    0.155
##     RLXNPIf_low             -0.177    0.102   -1.733    0.083   -0.177   -0.272
##     RLXNPIm                  0.195    0.078    2.494    0.013    0.195    0.246
##   Partner_enhancement_m ~                                                      
##     zNPIm                    0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf_low               -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf                 0.492    0.122    4.035    0.000    0.492    0.568
##     RLXNPIm                 -0.137    0.069   -1.972    0.049   -0.137   -0.177
##     RLXNPIf_low             -0.151    0.091   -1.662    0.097   -0.151   -0.237
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf_low ~~                                                         
##     zNPIm                     0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf_low              -0.196    0.151   -1.301    0.193   -0.196
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.072
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf_low              -0.172    0.147   -1.169    0.242   -0.172
##     RLXNPIm                   0.007    0.120    0.060    0.952    0.007
##   zMonthsf ~~                                                          
##     RLXNPIf_low               1.060    0.188    5.650    0.000    1.060
##     RLXNPIm                   0.183    0.123    1.489    0.136    0.183
##   RLXNPIf_low ~~                                                       
##     RLXNPIm                   0.307    0.168    1.824    0.068    0.307
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##    -0.143
##    -0.064
##          
##    -0.093
##    -0.129
##     0.007
##          
##     0.783
##     0.165
##          
##     0.203
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.038    0.125   40.249    0.000    5.038    5.705
##    .Prtnr_nhncmnt_    4.593    0.111   41.341    0.000    4.593    5.318
##     zNPIf_low         1.038    0.110    9.445    0.000    1.038    1.030
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.038   -0.038
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf_low      -0.136    0.148   -0.920    0.357   -0.136   -0.100
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf_low         1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm             0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf_low       1.843    0.284    6.481    0.000    1.843    1.000
##     RLXNPIm           1.242    0.192    6.481    0.000    1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356
#High narcissism - women
Study3$zNPIf_high <- (Study3$zNPIf - 1)
Study3$RLXNPIf_high <- Study3$zMonthsf*Study3$zNPIf_high

Model3_highw<- '
Partner_enhancement_f ~ zNPIf_high + zNPIm + zMonthsf + a2*RLXNPIf_high + RLXNPIm
Partner_enhancement_m ~ zNPIm + zNPIf_high + zMonthsf + RLXNPIm + RLXNPIf_high
'
results_Model3_highw<- sem(Model3_highw, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model3_highw, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 16 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf_hgh                0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm                   -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf                -0.216    0.132   -1.643    0.100   -0.216   -0.244
##     RLXNPIf_h (a2)          -0.177    0.102   -1.733    0.083   -0.177   -0.252
##     RLXNPIm                  0.195    0.078    2.494    0.013    0.195    0.246
##   Partner_enhancement_m ~                                                      
##     zNPIm                    0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf_hgh               -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf                 0.191    0.117    1.635    0.102    0.191    0.220
##     RLXNPIm                 -0.137    0.069   -1.972    0.049   -0.137   -0.177
##     RLXNPIf_h               -0.151    0.091   -1.662    0.097   -0.151   -0.219
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf_high ~~                                                        
##     zNPIm                     0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf_high              0.076    0.138    0.551    0.582    0.076
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.072
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf_high              0.011    0.135    0.081    0.935    0.011
##     RLXNPIm                   0.007    0.120    0.060    0.952    0.007
##   zMonthsf ~~                                                          
##     RLXNPIf_high             -0.929    0.170   -5.456    0.000   -0.929
##     RLXNPIm                   0.183    0.123    1.489    0.136    0.183
##   RLXNPIf_high ~~                                                      
##     RLXNPIm                  -0.059    0.153   -0.383    0.701   -0.059
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##     0.060
##    -0.064
##          
##    -0.093
##     0.009
##     0.007
##          
##    -0.741
##     0.165
##          
##    -0.042
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.482    0.121   45.396    0.000    5.482    6.208
##    .Prtnr_nhncmnt_    4.320    0.107   40.297    0.000    4.320    5.001
##     zNPIf_high       -0.962    0.110   -8.760    0.000   -0.962   -0.956
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.038   -0.038
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf_high     -0.136    0.137   -0.991    0.322   -0.136   -0.108
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf_high        1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm             0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf_high      1.580    0.244    6.481    0.000    1.580    1.000
##     RLXNPIm           1.242    0.192    6.481    0.000    1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356

Supplemeantry: simple slopes2

Alternatively, we can streamline the procedure within lavaan by defining a new parameter (: operator), which allows for direct estimation of the interaction effects without manually shifting data points.

Model_unrestricted<- '
Partner_enhancement_f ~ zNPIf + zNPIm + af*zMonthsf + iaf*RLXNPIf+ ipf*RLXNPIm
Partner_enhancement_m ~ zNPIm + zNPIf + am*zMonthsf + iam*RLXNPIm + ipm*RLXNPIf

f_low := af - iaf
f_high := af + iaf
m_low := am - iam
m_high := am + iam
'
results_Model_unrestricted<- sem(Model_unrestricted, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model_unrestricted, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 8 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.000
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -766.438
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1602.875
##   Bayesian (BIC)                              1687.954
##   Sample-size adjusted Bayesian (SABIC)       1577.546
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.000
##   P-value H_0: RMSEA <= 0.050                       NA
##   P-value H_0: RMSEA >= 0.080                       NA
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.000
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf                    0.222    0.087    2.546    0.011    0.222    0.253
##     zNPIm                   -0.322    0.089   -3.616    0.000   -0.322   -0.359
##     zMonthsf  (af)          -0.039    0.088   -0.449    0.654   -0.039   -0.044
##     RLXNPIf  (iaf)          -0.177    0.102   -1.733    0.083   -0.177   -0.170
##     RLXNPIm  (ipf)           0.195    0.078    2.494    0.013    0.195    0.246
##   Partner_enhancement_m ~                                                      
##     zNPIm                    0.378    0.079    4.790    0.000    0.378    0.431
##     zNPIf                   -0.137    0.077   -1.764    0.078   -0.137   -0.159
##     zMonthsf  (am)           0.342    0.078    4.392    0.000    0.342    0.394
##     RLXNPIm  (iam)          -0.137    0.069   -1.972    0.049   -0.137   -0.177
##     RLXNPIf  (ipm)          -0.151    0.091   -1.662    0.097   -0.151   -0.148
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.184    0.062   -2.950    0.003   -0.184
##   zNPIf ~~                                                             
##     zNPIm                     0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.060
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.072
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.081
##     RLXNPIm                   0.007    0.120    0.060    0.952    0.007
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478    0.066
##     RLXNPIm                   0.183    0.123    1.489    0.136    0.183
##   RLXNPIf ~~                                                           
##     RLXNPIm                   0.124    0.104    1.197    0.231    0.124
##   Std.all
##          
##    -0.340
##          
##     0.209
##    -0.136
##    -0.070
##    -0.064
##          
##    -0.093
##    -0.096
##     0.007
##          
##     0.078
##     0.165
##          
##     0.132
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.260    0.087   60.720    0.000    5.260    5.956
##    .Prtnr_nhncmnt_    4.456    0.077   57.955    0.000    4.456    5.160
##     zNPIf             0.038    0.110    0.342    0.732    0.038    0.037
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.038   -0.038
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.136   -0.161
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.610    0.094    6.481    0.000    0.610    0.782
##    .Prtnr_nhncmnt_    0.480    0.074    6.481    0.000    0.480    0.644
##     zNPIf             1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm             0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf           0.717    0.111    6.481    0.000    0.717    1.000
##     RLXNPIm           1.242    0.192    6.481    0.000    1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.218
##     Prtnr_nhncmnt_    0.356
## 
## Defined Parameters:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##     f_low             0.138    0.137    1.002    0.316    0.138    0.125
##     f_high           -0.216    0.132   -1.643    0.100   -0.216   -0.214
##     m_low             0.479    0.112    4.277    0.000    0.479    0.571
##     m_high            0.205    0.096    2.133    0.033    0.205    0.218
fitMeasures(results_Model_unrestricted, "df")
## df 
##  0

Restricted model

** Model 1: a fully restricted model in which all path coefficients were set equal across partners

** Model 2: Saturated model (results_Model_unrestricted)

** Model 3: equal actor and interaction effects

** Model 4: equal actor effect and zero interaction effect

Model1<- '
Partner_enhancement_f ~ a1*zNPIf + a2*zNPIm + a3*zMonthsf + a4*RLXNPIf + a5*RLXNPIm
Partner_enhancement_m ~ a1*zNPIm + a2*zNPIf + a3*zMonthsf + a4*RLXNPIm + a5*RLXNPIf
'
results_Model1<- sem(Model1, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
fitMeasures(results_Model1, "df")
## df 
##  5
anova(results_Model_unrestricted, results_Model1)
## 
## Chi-Squared Difference Test
## 
##                            Df    AIC    BIC  Chisq Chisq diff  RMSEA Df diff
## results_Model_unrestricted  0 1602.9 1688.0  0.000                          
## results_Model1              5 1611.2 1684.1 18.293     18.293 0.1779       5
##                            Pr(>Chisq)   
## results_Model_unrestricted              
## results_Model1               0.002601 **
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Model 1 fit the data significantly worse than Model 2, \(\chi^2(5) = 20.66\), \(p = .001\).

#candidate model
Model3 <- '
Partner_enhancement_f ~ a1*zNPIf + zNPIm + zMonthsf + a3*RLXNPIf + RLXNPIm
Partner_enhancement_m ~ a1*zNPIm + zNPIf + zMonthsf + a3*RLXNPIm + RLXNPIf
'
results_Model3<- sem(Model3, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
fitMeasures(results_Model3, "df")
## df 
##  2
#comparison of model fit: candidate (partially restricted) model against saturated model
anova(results_Model_unrestricted, results_Model3)
## 
## Chi-Squared Difference Test
## 
##                            Df    AIC  BIC  Chisq Chisq diff RMSEA Df diff
## results_Model_unrestricted  0 1602.9 1688 0.0000                         
## results_Model3              2 1600.8 1681 1.9496     1.9496     0       2
##                            Pr(>Chisq)
## results_Model_unrestricted           
## results_Model3                 0.3773
#model with interaction effects zeroed
Model4 <- '
Partner_enhancement_f ~ a1*zNPIf + zNPIm + zMonthsf + 0*RLXNPIf + RLXNPIm
Partner_enhancement_m ~ a1*zNPIm + zNPIf + zMonthsf + 0*RLXNPIm + RLXNPIf
'
results_Model4<- sem(Model4, data=Study3, meanstructure = TRUE, fixed.x = FALSE)

#comparison of model fit: model with interaction effects zeroed against candidate model
anova(results_Model_unrestricted, results_Model4)
## 
## Chi-Squared Difference Test
## 
##                            Df    AIC    BIC  Chisq Chisq diff   RMSEA Df diff
## results_Model_unrestricted  0 1602.9 1688.0 0.0000                           
## results_Model4              3 1604.8 1682.6 7.9764     7.9764 0.14053       3
##                            Pr(>Chisq)  
## results_Model_unrestricted             
## results_Model4                 0.0465 *
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Model 3 did not fit the data significantly worse than Model 2, \(\chi^2(2) = 1.95\), \(p = 0.377\).

summary(results_Model3, fit.measures=TRUE, standardized=TRUE, rsquare = TRUE)
## lavaan 0.6.16 ended normally after 23 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
##   Number of equality constraints                     2
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 1.950
##   Degrees of freedom                                 2
##   P-value (Chi-square)                           0.377
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.005
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -767.412
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1600.825
##   Bayesian (BIC)                              1681.042
##   Sample-size adjusted Bayesian (SABIC)       1576.943
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.214
##   P-value H_0: RMSEA <= 0.050                    0.450
##   P-value H_0: RMSEA >= 0.080                    0.451
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.025
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   Partner_enhancement_f ~                                                      
##     zNPIf     (a1)           0.309    0.061    5.082    0.000    0.309    0.345
##     zNPIm                   -0.310    0.089   -3.476    0.001   -0.310   -0.338
##     zMonthsf                -0.029    0.088   -0.333    0.739   -0.029   -0.032
##     RLXNPIf   (a3)          -0.146    0.059   -2.483    0.013   -0.146   -0.137
##     RLXNPIm                  0.200    0.078    2.547    0.011    0.200    0.247
##   Partner_enhancement_m ~                                                      
##     zNPIm     (a1)           0.309    0.061    5.082    0.000    0.309    0.360
##     zNPIf                   -0.151    0.077   -1.953    0.051   -0.151   -0.179
##     zMonthsf                 0.336    0.078    4.331    0.000    0.336    0.396
##     RLXNPIm   (a3)          -0.146    0.059   -2.483    0.013   -0.146   -0.192
##     RLXNPIf                 -0.165    0.089   -1.856    0.063   -0.165   -0.165
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|)   Std.lv
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.187    0.063   -2.965    0.003   -0.187
##   zNPIf ~~                                                             
##     zNPIm                     0.207    0.111    1.872    0.061    0.207
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.136
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.060
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.072
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.092
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.081
##     RLXNPIm                   0.007    0.120    0.060    0.952    0.007
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478    0.066
##     RLXNPIm                   0.183    0.123    1.489    0.136    0.183
##   RLXNPIf ~~                                                           
##     RLXNPIm                   0.124    0.104    1.197    0.231    0.124
##   Std.all
##          
##    -0.342
##          
##     0.209
##    -0.136
##    -0.070
##    -0.064
##          
##    -0.093
##    -0.096
##     0.007
##          
##     0.078
##     0.165
##          
##     0.132
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    5.262    0.086   60.937    0.000    5.262    5.831
##    .Prtnr_nhncmnt_    4.451    0.077   57.774    0.000    4.451    5.256
##     zNPIf             0.038    0.110    0.342    0.732    0.038    0.037
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.038   -0.038
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.000   -0.000
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.136   -0.161
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Prtnr_nhncmnt_    0.618    0.095    6.481    0.000    0.618    0.759
##    .Prtnr_nhncmnt_    0.486    0.075    6.481    0.000    0.486    0.677
##     zNPIf             1.014    0.156    6.481    0.000    1.014    1.000
##     zNPIm             0.971    0.150    6.481    0.000    0.971    1.000
##     zMonthsf          0.994    0.153    6.481    0.000    0.994    1.000
##     RLXNPIf           0.717    0.111    6.481    0.000    0.717    1.000
##     RLXNPIm           1.242    0.192    6.481    0.000    1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.241
##     Prtnr_nhncmnt_    0.323

Restricted model simple slopes

Model3 <- '
Partner_enhancement_f ~ a1*zNPIf + zNPIm + af*zMonthsf + a3*RLXNPIf + a4*RLXNPIm
Partner_enhancement_m ~ a1*zNPIm + zNPIf + am*zMonthsf + a3*RLXNPIm + a5*RLXNPIf

#actor
alowf := af - a3
ahighf := af + a3
alowm := am - a3
ahighm := am + a3

plowf := af - a5
phighf := af + a5
plowm := am - a4
phighm := am + a4
'
results_Model3<- sem(Model3, data=Study3, meanstructure = TRUE, fixed.x = FALSE)
summary(results_Model3, fit.measures = TRUE, standardize=TRUE, rsquare=TRUE, ci = TRUE)
## lavaan 0.6.16 ended normally after 23 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        35
##   Number of equality constraints                     2
## 
##   Number of observations                            84
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 1.950
##   Degrees of freedom                                 2
##   P-value (Chi-square)                           0.377
## 
## Model Test Baseline Model:
## 
##   Test statistic                                67.974
##   Degrees of freedom                                11
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    1.000
##   Tucker-Lewis Index (TLI)                       1.005
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)               -767.412
##   Loglikelihood unrestricted model (H1)       -766.438
##                                                       
##   Akaike (AIC)                                1600.825
##   Bayesian (BIC)                              1681.042
##   Sample-size adjusted Bayesian (SABIC)       1576.943
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.000
##   90 Percent confidence interval - lower         0.000
##   90 Percent confidence interval - upper         0.214
##   P-value H_0: RMSEA <= 0.050                    0.450
##   P-value H_0: RMSEA >= 0.080                    0.451
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.025
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Expected
##   Information saturated (h1) model          Structured
## 
## Regressions:
##                           Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##   Partner_enhancement_f ~                                                      
##     zNPIf     (a1)           0.309    0.061    5.082    0.000    0.190    0.428
##     zNPIm                   -0.310    0.089   -3.476    0.001   -0.484   -0.135
##     zMonthsf  (af)          -0.029    0.088   -0.333    0.739   -0.201    0.142
##     RLXNPIf   (a3)          -0.146    0.059   -2.483    0.013   -0.261   -0.031
##     RLXNPIm   (a4)           0.200    0.078    2.547    0.011    0.046    0.353
##   Partner_enhancement_m ~                                                      
##     zNPIm     (a1)           0.309    0.061    5.082    0.000    0.190    0.428
##     zNPIf                   -0.151    0.077   -1.953    0.051   -0.302    0.001
##     zMonthsf  (am)           0.336    0.078    4.331    0.000    0.184    0.488
##     RLXNPIm   (a3)          -0.146    0.059   -2.483    0.013   -0.261   -0.031
##     RLXNPIf   (a5)          -0.165    0.089   -1.856    0.063   -0.339    0.009
##    Std.lv  Std.all
##                   
##     0.309    0.345
##    -0.310   -0.338
##    -0.029   -0.032
##    -0.146   -0.137
##     0.200    0.247
##                   
##     0.309    0.360
##    -0.151   -0.179
##     0.336    0.396
##    -0.146   -0.192
##    -0.165   -0.165
## 
## Covariances:
##                            Estimate  Std.Err  z-value  P(>|z|) ci.lower
##  .Partner_enhancement_f ~~                                             
##    .Prtnr_nhncmnt_           -0.187    0.063   -2.965    0.003   -0.311
##   zNPIf ~~                                                             
##     zNPIm                     0.207    0.111    1.872    0.061   -0.010
##     zMonthsf                 -0.136    0.111   -1.231    0.218   -0.353
##     RLXNPIf                  -0.060    0.093   -0.642    0.521   -0.243
##     RLXNPIm                  -0.072    0.123   -0.587    0.557   -0.312
##   zNPIm ~~                                                             
##     zMonthsf                 -0.092    0.108   -0.850    0.395   -0.303
##     RLXNPIf                  -0.081    0.092   -0.880    0.379   -0.260
##     RLXNPIm                   0.007    0.120    0.060    0.952   -0.228
##   zMonthsf ~~                                                          
##     RLXNPIf                   0.066    0.092    0.709    0.478   -0.116
##     RLXNPIm                   0.183    0.123    1.489    0.136   -0.058
##   RLXNPIf ~~                                                           
##     RLXNPIm                   0.124    0.104    1.197    0.231   -0.079
##  ci.upper   Std.lv  Std.all
##                            
##    -0.063   -0.187   -0.342
##                            
##     0.424    0.207    0.209
##     0.081   -0.136   -0.136
##     0.123   -0.060   -0.070
##     0.168   -0.072   -0.064
##                            
##     0.120   -0.092   -0.093
##     0.099   -0.081   -0.096
##     0.242    0.007    0.007
##                            
##     0.247    0.066    0.078
##     0.424    0.183    0.165
##                            
##     0.328    0.124    0.132
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##    .Prtnr_nhncmnt_    5.262    0.086   60.937    0.000    5.092    5.431
##    .Prtnr_nhncmnt_    4.451    0.077   57.774    0.000    4.300    4.602
##     zNPIf             0.038    0.110    0.342    0.732   -0.178    0.253
##     zNPIm            -0.038    0.108   -0.350    0.727   -0.248    0.173
##     zMonthsf         -0.000    0.109   -0.002    0.998   -0.213    0.213
##     RLXNPIf          -0.136    0.092   -1.473    0.141   -0.317    0.045
##     RLXNPIm          -0.092    0.122   -0.753    0.452   -0.330    0.147
##    Std.lv  Std.all
##     5.262    5.831
##     4.451    5.256
##     0.038    0.037
##    -0.038   -0.038
##    -0.000   -0.000
##    -0.136   -0.161
##    -0.092   -0.082
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##    .Prtnr_nhncmnt_    0.618    0.095    6.481    0.000    0.431    0.805
##    .Prtnr_nhncmnt_    0.486    0.075    6.481    0.000    0.339    0.632
##     zNPIf             1.014    0.156    6.481    0.000    0.707    1.320
##     zNPIm             0.971    0.150    6.481    0.000    0.678    1.265
##     zMonthsf          0.994    0.153    6.481    0.000    0.694    1.295
##     RLXNPIf           0.717    0.111    6.481    0.000    0.500    0.934
##     RLXNPIm           1.242    0.192    6.481    0.000    0.866    1.617
##    Std.lv  Std.all
##     0.618    0.759
##     0.486    0.677
##     1.014    1.000
##     0.971    1.000
##     0.994    1.000
##     0.717    1.000
##     1.242    1.000
## 
## R-Square:
##                    Estimate
##     Prtnr_nhncmnt_    0.241
##     Prtnr_nhncmnt_    0.323
## 
## Defined Parameters:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##     alowf             0.117    0.105    1.115    0.265   -0.088    0.322
##     ahighf           -0.175    0.106   -1.649    0.099   -0.383    0.033
##     alowm             0.482    0.103    4.698    0.000    0.281    0.683
##     ahighm            0.190    0.092    2.070    0.038    0.010    0.370
##     plowf             0.136    0.124    1.091    0.275   -0.108    0.379
##     phighf           -0.194    0.125   -1.550    0.121   -0.439    0.051
##     plowm             0.136    0.108    1.265    0.206   -0.075    0.348
##     phighm            0.536    0.113    4.751    0.000    0.315    0.757
##    Std.lv  Std.all
##     0.117    0.105
##    -0.175   -0.169
##     0.482    0.533
##     0.190    0.259
##     0.136    0.133
##    -0.194   -0.197
##     0.136    0.149
##     0.536    0.642

Similar results has been reported in Czarna et al (2022) pages, 104212 - 104213:

-Actor effect

“Relationship duration negatively predicted partner-enhancement among men low on narcissism (\(-1\) SD: \(b = -0.50\), \(SE = 0.11\), \(Z = -4.70\), \(p < .001\)). It also did so among men high on narcissism, but substantially less strongly (\(+1\) SD: \(b = -0.20\), \(SE = 0.10\), \(Z = -2.07\), \(p = .038\); Fig. 1). Importantly, the latter slope was significantly less steep than the former, \(p = .047\). However, the effects of relationship duration were not significant for women low (\(-1\) SD: \(b = -0.12\), \(SE = 0.13\), \(Z = -1.12\), \(p = .265\)) or high (\(+1\) SD: \(b = 0.18\), \(SE = 0.11\), \(Z = 1.65\), \(p = .100\)) on narcissism. Additionally, these two slopes were not significantly different. As indicated above, a formal test showed that the omnibus interaction (\(a_1\)) among men was not significantly different than among women, suggesting no three-way interaction (involving gender). In all, although women low on narcissism partner-enhanced at short and long relationship duration (just less so at long relationship duration), those high on narcissism self-enhanced at short and long relationship duration. Further, although men low on narcissism partner-enhanced less the longer the relationship was (hence the effect was detectable at short but not at long relationship duration), those high on narcissism self-enhanced both at short and long relationship duration.”

-Partner effect

“Partner narcissism positively and significantly predicted partner-enhancement at short relationship duration (2.7 months: \(b = 0.611\), \(SE = 0.149\), \(Z = 4.099\), \(p < .001\)), and positively but trendingly at long relationship duration (56.7 months: \(b = 0.192\), \(SE = 0.107\), \(Z = 1.791\), \(p = .073\), Fig. 2). Women who had a narcissistic partner engaged in partner-enhancement early on in their relationships. We will not interpret the interaction for men, as the relevant omnibus effect was not significant.”