Measurement equivalence and differential item function of aggression in US college student and general adult samples

This analysis aims to replicate exploratory analyses done to supplement another project by Ben Rudolph, Adam Panish, and Andrew Delton (see descriptions here: https://osf.io/e5j9q/overview and here: https://osf.io/2ejz6/overview). These exploratory analyses involved 3 stages: 1) Testing for measurement invariance in the Short-Form Aggression Scale between the authors' general US adult and college students samples. The results showed that there was not measurement invariance between college students and general adults. 2) Performing differential item function analysis to explore which items on the Short Form Aggression Scale, if any, exhibited equivalent measurement capabilities across samples; three items were found to function equivalently across general adults and college students. 3) Re-testing the authors' hypotheses using the three-item equivalent aggression scale; all previous findings were the same except the interaction between trait aggression and the experimental treatment doubled in size when predicting respondents' anger at a hypothetical tax increase. This suggests that the null interaction effect originally observed may result from measurement inequivalence of aggression in college students rather than being a true null effect. This would give the authors backing to interpret the results from this college student sample in a manner consistent with their previous two samples, which both found a statistically significant interaction effect. The goal of the present study is to replicate the measurement invariance and differential item functioning analyses. Specifically, we will collect data from a new sample of college students to test whether we still see inequivalent measurement of aggression between general adults and college students and if the three equivalent aggression items identified in the exploratory analysis emerge in new data as well. For reference, the three equivalent items revealed in the exploratory analysis were: "There are people who have pushed me so far that we have come to blows" "I have trouble controlling my temper" "Sometimes I fly off the handle for no good reason".