Prejudiced interactions: implicit racial bias reduces predictive simulation during joint action with an out-group avatar.

Lucia Maria Sacheli,Nick Taubert,Enea Francesco Pavone,Salvatore Maria Aglioti,Andrea Christensen,Martin A Giese,Matteo Candidi

doi:10.1038/srep08507

Abstract

During social interactions people automatically apply stereotypes in order to rapidly categorize others. Racial differences are among the most powerful cues that drive these categorizations and modulate our emotional and cognitive reactivity to others. We investigated whether implicit racial bias may also shape hand kinematics during the execution of realistic joint actions with virtual in- and out-group partners. Caucasian participants were required to perform synchronous imitative or complementary reach-to-grasp movements with avatars that had different skin color (white and black) but showed identical action kinematics. Results demonstrate that stronger visuo-motor interference (indexed here as hand kinematics differences between complementary and imitative actions) emerged: i) when participants were required to predict the partner's action goal in order to on-line adapt their own movements accordingly; ii) during interactions with the in-group partner, indicating the partner's racial membership modulates interactive behaviors. Importantly, the in-group/out-group effect positively correlated with the implicit racial bias of each participant. Thus visuo-motor interference during joint action, likely reflecting predictive embodied simulation of the partner's movements, is affected by cultural inter-individual differences.

Highlights

During social interactions people automatically apply stereotypes in order to rapidly categorize others
We hypothesize that: i) group bias modulations of visuo-motor interference effects are more evident under conditions where sensorimotor simulations are essential to predict the goal of the others’ movements compared to when this prediction is unnecessary to one’s own action fulfillment; ii) these sensorimotor simulations are captured in movement kinematics
As to the in-group/out-group effect, we aimed to investigate: i) whether previous findings on the in-group/out-group modulation of sensorimotor simulation evoked by the observation of others’ action/pain[8,9,10,11,12] can be measured in the kinematics of face-to-face interactions, and ii) whether these modulations are selectively linked to action prediction

Summary

Introduction

During social interactions people automatically apply stereotypes in order to rapidly categorize others. Results demonstrate that stronger visuo-motor interference (indexed here as hand kinematics differences between complementary and imitative actions) emerged: i) when participants were required to predict the partner’s action goal in order to on-line adapt their own movements ; ii) during interactions with the in-group partner, indicating the partner’s racial membership modulates interactive behaviors. No study has so far tested whether group bias modulates face-to-face motor interactions that require individuals to mutually adjust their movements on-line Studying such situations is crucial for understanding the impact of group bias on action prediction and sensorimotor simulation mechanisms as indirectly indexed by actual movement parameters. We hypothesize that: i) group bias modulations of visuo-motor interference effects are more evident under conditions where sensorimotor simulations are essential to predict the goal of the others’ movements compared to when this prediction is unnecessary to one’s own action fulfillment; ii) these sensorimotor simulations are captured in movement kinematics. Finding these results would suggest that in-group/out-group modulation of sensorimotor simulation in joint action is linked to action prediction

Methods

Results

Conclusion