Assessing and correcting for regression toward the mean in deviance-induced social conformity

Abstract

Our understanding of the mechanisms underlying social conformity has recently advanced due to the employment of neuroscience methodology and novel experimental approaches. Most prominently, several studies have demonstrated the role of neural reinforcement-learning processes in conformal adjustments using a specifically designed and frequently replicated paradigm. Only very recently, the validity of the critical behavioral effect in this very paradigm was seriously questioned, as it invites the unwanted contribution of regression toward the mean. Using a straightforward control-group design, we corroborate this recent finding and demonstrate the involvement of statistical distortions. Additionally, however, we provide conclusive evidence that the paradigm nevertheless captures behavioral effects that can only be attributed to social influence. Finally, we present a mathematical approach that allows to isolate and quantify the paradigm’s true conformity effect both at the group level and for each individual participant. These data as well as relevant theoretical considerations suggest that the groundbreaking findings regarding the brain mechanisms of social conformity that were obtained with this recently criticized paradigm were indeed valid. Moreover, we support earlier suggestions that distorted behavioral effects can be rectified by means of appropriate correction procedures.

Investigating the Genetic Basis of Social Conformity: The Role of the Dopamine Receptor 3 <b><i>(DRD3)</i></b> Gene

“…Regression analysis again revealed a significant association between the polymorphism and the corrected conformity score [F(1, 146) = 5.074, p = 0.026, β = 0.183, R 2 = 0.034, and adjusted R 2 = 0.027; table 1]. Considering the potential group differences between our study and that of Schnuerch et al [39], we also varied γ 10 with ±1 SE and ±2 SE (i.e. -0.412, -0.393, -0.355, and -0.336).…”

“…Figure 3A of Yu and Chen [38] and figure 2B of Schnuerch et al [39] show that the sizes of the effect of the initial ratings on rating change were very similar even though the two studies were conducted in different cultures (one on Chinese and the other on Germans). Given that we used essentially the same task as Yu and Chen [38] and Schnuerch et al [39] for the assessment of conformity behavior, we used the parameter γ 10 (-0.374) from the control group of Schnuerch et al [39] to estimate the corrected rating change for each item for each participant in the current study and conducted regression analyses with the corrected rating change as the outcome variable. The corrected conformity score (mean ± SD: 0.103 ± 0.105, range -0.168 to 0.419) was still significantly higher than zero [t(147) = 11.887, p < 0.001].…”

“…To avoid potential effects of mating motivation on facial attractiveness ratings, only female faces and female participants were selected in previous studies [3,39]. However, in our study, both male and female participants were recruited to rate the attractiveness of both male and female faces.…”

“…Additionally, Schnuerch et al [39] introduced a new approach that could isolate and quantify the conformity effect from a different perspective. They added a control group in which no group rating was ever shown and estimated the average effect of the initial ratings on the rating change (i.e.…”

Social Norms Shift Preferences for Healthy and Unhealthy Foods

“…We conducted a mixed effects analysis to compare participants’ rating shift across trial type, entering feedback type (i.e., Peers Lower, Peers Same, Peers Higher) as a fixed effect and participant as a random effect. We also entered participants’ initial ratings for each trial as a fixed effect covariate to control for the possibility that our results could be explained by regression to the mean [37]. Note that this analysis did not include information about the type of food (healthy versus unhealthy) participants viewed in each trial.…”