Body Motion Cues Drive First Impressions: Consensus, Truth and the Origins of Personality Trait Judgements based on Targets' Whole-Body Motion.

Abstract

Personality trait attribution is automatic, and first impressions can be lasting and lead to important social decisions. Research on how facial cues impact on person perception is plentiful, but less is known about how whole-body motion contributes to first impressions. This thesis presents results from experiments in which participants rated the traits of target individuals based solely on short, silent movie clips of those individuals performing actions or expressing emotions with their bodies, or simply walking. To isolate the contribution to trait attribution of body motion cues, the static form information of the body stimuli was degraded. Consensus at zero acquaintance is replicated throughout the thesis, as manifested by strong inter-rater agreement for all rating experiments and within all displayed behaviours, thus indicating that body motion may contain visual cues that drive trait impressions. Further experiments identified motion parameters that predict personality trait impressions, and an experimental paradigm showed that computational manipulation of motion data can indeed change observer judgements of computerised models based on human motion data. No accuracy was found in the trait judgements, in that there was no link between how a target was judged and this target individual's scores on a five-factor personality questionnaire. Underlying judgements driving personality trait impressions were found: impressions of emotions, attractiveness and masculinity appear to be intertwined with personality trait judgements. Finally, patterns in personality trait judgements based on body motion were consistent with findings from studies on face perception, reflecting a two-step judgement of a target person's intention and ability to cause harm. Differences were found depending on the display format of the stimuli, and interpretations for these discrepancies are offered. The thesis shows that people go beyond the information available to them when forming personality trait impressions of strangers, and offers evidence that changes in body motion may indeed have an impact on such trait impressions.