Who reports it best? A comparison between parent-report, self-report, and the real life social behaviors of adults with Williams syndrome.

Given the reliance on self-report in studies of adults with intellectual disabilities, this study examined individual vs. parental reports concerning the social approach behaviors of adults with Williams syndrome (WS) across a hypothetical and a live behavioral setting. Individuals with WS (N = 30) were asked whether they would approach strangers in two hypothetical, laboratory tasks (yes/no questionnaire vs. judging facial stimuli of individuals with different emotional expressions). Similarly, their parents also responded to a rating scale of their child's social approach behavior toward strangers displaying various emotions. Then, in a community setting, behavioral coders recorded actual social approaches of individuals with WS toward strangers. Although self-report ratings were consistent across measures, these measures did not correspond to the individuals' actual behaviors during the community observations. Conversely, parental reports did not correspond to their child's self-report measures, but parents did more accurately predict their child's real-life social approach behaviors. Implications are discussed for both research and practice.