The true role that suppressor effects play in condition-based regression analysis: None. A reply to Fiedler (2021)

Humberg, S; Dufner, M; Schönbrodt, F D; Geukes, K; Hutteman, R; van Zalk, M H W; Denissen, J J A; Nestler, S & Back, M D

Abstract

Condition-based regression analysis (CRA) is a statistical method for testing self-enhancement effects. That is, CRA indicates whether, in a set of empirical data, people with higher values on the directed discrepancy self-view S minus reality criterion R (i.e., S-R) tend to have higher values on some outcome variable (e.g., happiness). In a critical comment, Fiedler (2021) claims that CRA yields inaccurate conclusions in data with a suppressor effect. Here, we show that Fiedler’s critique is unwarranted. All data that are simulated in his comment show a positive association between S-R and H, which is accurately detected by CRA. By construction, CRA indicates an association between S-R and H only when it is present in the data. In contrast to Fiedler’s claim, it also yields valid conclusions when the outcome variable is related only to the self-view or when there is a suppressor effect. Our clarifications provide guidance for evaluating Fiedler’s comment, clear up with the common heuristic that suppressor effects are always problematic, and assist readers in fully understanding CRA.