Primary results
Explicit comparison
Participants were explicitly asked to compare the population to the sample: “Do you think the Zarpies on Zarpie island are shorter, the same, or taller in height than the Zarpies who visited?”
We pre-registered that if adults do adjust, they should be more likely to say “taller” in the skewed condition than the not skewed condition for both the visible and occluded sets of conditions.
Notably, “the same” is an extremely common response across all conditions.
| boarding | shorter | the same | taller |
|---|---|---|---|
| not skewed | 8% | 80% | 12% |
| skewed | 5% | 70% | 25% |
## # weights: 9 (4 variable)
## initial value 218.623845
## iter 10 value 137.744908
## iter 10 value 137.744907
## final value 137.744907
## converged
## # weights: 6 (2 variable)
## initial value 218.623845
## iter 10 value 140.831356
## iter 10 value 140.831356
## iter 10 value 140.831356
## final value 140.831356
## converged## Analysis of Deviance Table (Type II tests)
##
## Response: dv_comp
## LR Chisq Df Pr(>Chisq)
## boarding 6.1729 2 0.04566 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1As predicted, participants’ explicit comparisons were significantly different between conditions (LR Chisq(2) = 6.17, = 0.046).
##
## Call:
## glm(formula = dv_comp_taller ~ boarding, family = binomial, data = .)
##
## Coefficients:
## Estimate Std. Error z value Pr(>|z|)
## (Intercept) -1.9924 0.3077 -6.475 0.000000000095 ***
## boardingskewed 0.9072 0.3850 2.357 0.0184 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## (Dispersion parameter for binomial family taken to be 1)
##
## Null deviance: 191.15 on 198 degrees of freedom
## Residual deviance: 185.27 on 197 degrees of freedom
## AIC: 189.27
##
## Number of Fisher Scoring iterations: 4##
## Call:
## glm(formula = dv_comp_same ~ boarding, family = binomial, data = .)
##
## Coefficients:
## Estimate Std. Error z value Pr(>|z|)
## (Intercept) 1.3863 0.2500 5.545 0.0000000294 ***
## boardingskewed -0.5534 0.3322 -1.666 0.0957 .
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## (Dispersion parameter for binomial family taken to be 1)
##
## Null deviance: 224.36 on 198 degrees of freedom
## Residual deviance: 221.54 on 197 degrees of freedom
## AIC: 225.54
##
## Number of Fisher Scoring iterations: 4##
## Call:
## glm(formula = dv_comp_shorter ~ boarding, family = binomial,
## data = .)
##
## Coefficients:
## Estimate Std. Error z value Pr(>|z|)
## (Intercept) -2.4423 0.3686 -6.626 0.0000000000345 ***
## boardingskewed -0.4915 0.5886 -0.835 0.404
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## (Dispersion parameter for binomial family taken to be 1)
##
## Null deviance: 96.069 on 198 degrees of freedom
## Residual deviance: 95.354 on 197 degrees of freedom
## AIC: 99.354
##
## Number of Fisher Scoring iterations: 5Specifically, participants were more likely to say that Zarpies on Zarpie island are “taller”, in the skewed condition compared to not skewed condition (z = 2.36, = 0.018).
Participants did not show any significant differences across conditions in their likelihood of saying that Zarpies on Zarpie island are “the same” (z = -1.67, = 0.096) or that they are “shorter” (z = -0.84, = 0.404).