A methodological note on the interactive and main effects of dualistic personality dimensions: An example using the 2 × 2 model of perfectionism

The goal of this methodological note was to outline the importance of considering the interactive and main effects of dualistic personality dimensions by presenting an example grounded in the 2 × 2 model of perfectionism (Gaudreau & Thompson, 2010). A study was conducted with a sample of 98 university students to examine the associations between four subtypes of perfectionism and academic performance. Results of moderated regression analyses revealed a non-significant interaction between self-oriented (SOP) and socially prescribed perfectionism (SPP). Nonetheless, the four hypotheses of the 2 × 2 model of perfectionism were supported in the context of a compensatory model showing a significant and positive main effect of SOP along with a negative and significant main effect of SPP. This methodological note contributes to the literature by offering clear guidelines on how the two main effects of SOP and SPP (and their resulting predicted values) can be used to test the four hypotheses of the 2 × 2 model despite the absence of a significant interaction between SOP and SPP.

► Four subtypes of perfectionism are distinctively associated with academic performance.
► These hypotheses can be tested using main effects in multiple regressions.
► Pure self-oriented perfectionism is associated with higher GPA than non-perfectionism.
► Results support the 2 × 2 model of dispositional perfectionism.