The detrimental effects of atypical nonverbal behavior on older adults’ first impressions of individuals with Parkinson’s disease.

After viewing short video clips of individuals with Parkinson's disease (PD) who varied in the symptoms of facial masking (reduced expressivity) and abnormal bodily movement (ABM: including tremor and related movement disorders), older adult observers provided their first impressions of targets' social positivity. Impressions of targets with higher masking or ABM were more negative than impressions of targets with lower masking or ABM. Furthermore, masking was more detrimental for impressions of women and when observers considered emotional relationship goals, whereas ABM was more detrimental for instrumental relationship goals. This study demonstrated the stigmatizing effects of both reduced and excessive movement.