The Evil At Hand: Effect of the Social Meaning of Objects on Motor Planning

When planning reach-to-grasp movements, individuals frequently face a tradeoff between biomechanical comfort (i.e., avoiding effortful actions) and "socio-emotional comfort" (i.e., avoiding decisions with a negative socio-emotional outcome). But what happens when socio-emotional comfort conflicts with biomechanical comfort? This study investigated whether and under what conditions individuals may prioritize socio-emotional over biomechanical comfort during motor planning. In a series of three experiments based on the end-state comfort effect, 88 participants selected one of two mugs which varied in orientation (i.e., upright/inverted) and social meaning (i.e., socially positive, neutral, or negative symbol printed on the mug). The findings confirmed that symbolic meaning may influence motor planning. This effect was however context-dependent, i.e. stronger when participants had a social instead of a functional goal (i.e., choosing a mug to give it as a present vs. to use it). In this condition, participants prioritized socio-emotional comfort over their own biomechanical comfort. The findings suggest that individuals integrate social information (e.g., social norms) into motor plans. Furthermore, this information can sometimes bypass biomechanical constraints: when the social meaning of objects is salient (here, based on contrasts between positive and negative symbols) and context-relevant, biomechanical comfort can be sacrificed in favor of socio-emotional comfort.