When thinking, especially about cognitively demanding material, we often avert our gaze from the face of our interlocutor or other potentially distracting aspects of the visual environment (eg Glenberg, Schroeder, & Robertson, 1998; Phelps, Doherty-Sneddon, Warnock, 2006). Reasons why we might look away from faces in particular are that they are 'capturing', hard to ignore and physiologically arousing. Here we investigate whether: people with Williams Syndrome (WS) and autistic spectrum disorder (ASD) avert their gaze in response to cognitive demands placed upon them; and whether participants with WS experience increased physiological arousal associated with looking at faces. ASD is a well known developmental disorder which is associated with a number of emotional and intellectual difficulties. Williams syndrome is a rare genetic disorder which in terms of social functioning has been referred to as the 'other end of the spectrum' compared to individuals with ASD (Brock, Einav & Riby, in press). The proposed work has significant practical and clinical implications. For example while atypical patterns of eye gaze are reported in ASD our understanding of why this occurs remains limited, as do the cognitive implications of social skills training for this population.