Examining the Impact of Control Condition Design in Mimicry–Liking Link Research: How Motor Behavior May Impact Liking

Mimicry is an automatic imitation of an interacting partner’s behaviors. The most frequently researched consequence of being mimicked is liking. Yet there is little research on whether specific design of control conditions (i.e., variable behavior of the confederate across conditions) may affect study results. In this study, we compared the classical mimicry group with four control conditions: (i–ii) a confederate sits still or makes random movements (common in mimicry research), (iii) confederates receive no instructions regarding their nonverbal behavior (rarely observed in mimicry studies), and a condition that we created, in which (iv) a confederate makes atypical motor movements. Participants (N = 538) were interviewed by confederates, while the confederates’ behavior varied across conditions during the interviews. They mimicked the participants’ nonverbal behaviors (mimicry condition), sat still (no-movement condition), made random nonverbal movements unrelated to the participants (responsiveness condition), made repetitive body and object movements (repetitive behavior condition), or participated in the interview without any further instructions (double-blind condition). The confederate’s behavior influenced liking: χ2(4) = 40.7, p < 0.001, ε2 = 0.07. Participants liked the confederates more when the latter mimicked them than when they sat still (p < 0.001) or made repetitive movements (p = 0.008), but not when the confederates made random movements, and when they only engaged in the conversation (p > 0.5). There were also differences between the no-movements condition (i) and the responsiveness condition (p = 0.003), (ii) and the double-blind condition (p < 0.001). Because the two classical control conditions are treated interchangeably in mimicry studies, more attention should be paid to the methodological aspects of mimicry research. Additionally, a mini-metaanalysis was conducted.