Social difficulties are a defining feature of autism spectrum conditions (ASC). Recently it has been suggested that social symptoms of ASC may stem from a motivational deficit (Chevallier et al. 2012
). This social motivation theory proposes that social interactions are inherently rewarding and motivating for most typically developing people but this might not be true for people with ASC. Here we test if adolescents with ASC differ in their preference for viewing social/non-social movies, as a way to evaluate the social motivation theory.
Observations of the behaviour of children with autism in natural settings suggest fewer friendships and reciprocity (Chamberlain et al. 2007
) and adults with autism also report less desire for friendship (Baron-Cohen and Wheelwright 2003
). However, quantifying motivation in the lab is not always straightforward. Chevallier et al. (2012
) distinguish three domains of social motivation—orienting towards people; seeking out people and maintaining social relationships over the long term. We focus here on measuring the propensity to seek out others or find interaction with others rewarding, rather than just visual orienting towards particular stimuli. Approach-avoidance tasks have been used previously to understand the motivation to avoid fearful stimuli such as spiders (Rinck and Becker 2007
) or social stimuli in people with social anxiety (Heuer et al. 2007
). In this task, target stimuli are shown on a computer screen and participants can either pull the item towards themselves (making it larger) or push the item away (making it smaller) using the joystick, giving an estimate of their approach and avoidance preferences for the stimuli. Studies of social motivation in ASC using this type of task have shown some mixed results, including a higher approach tendency for all the stimuli (face as well as landscapes) in people with ASC (Deckers et al. 2014
) or greater approach for only the stimuli with higher incentive value for ASC (Silva et al. 2015
). Ewing et al. (2013
) also failed to find evidence of lower social preference in adolescents with ASC, and reported high preference for non-social stimuli in both ASC and typical groups. Similarly, Watson et al. (2015
) found that participants with ASC would accept lower monetary reward to look at high autism interest objects, while they were not different from typical groups for their preference for social or non-social objects.
There are several possible reasons for the mixed results reported above. One is the substantial heterogeneity in the symptom profiles and cognitive abilities within ASC (Freeth et al. 2011
; McPartland et al. 2011
). The other possible reason could be the difference in the tasks used and the age groups of the participants taken in these studies. There is increasing evidence that motivation to engage with different social groups changes over the course of typical adolescence (Foulkes and Blakemore 2016
), which could impact on the behaviour of both the autism and the typical control sample in the studies described above.
Here we use a simpler task, called Choose-A-Movie, which can measure social motivation in adults with ASC (Dubey et al. 2015
). The aim of the present study is to test if this autistic difference in social motivation is also present in adolescents, and to gain a deeper understanding of the development of social preference. Based on the theory of reduced social motivation and the previous findings from the original version of CAM paradigm with adults with ASC, it was expected that the adolescents with ASC would show reduced preference for social stimuli.