While both groups showed more verbal interactions compared to the free play periods, the TD group engaged roughly 92% of the time whereas the ASD group engaged in conversation with peers 74% of the time. Results == There were no differences between the groups during unsolicited free play; however, during solicited play by the confederate, significant differences emerged such that children with ASD engaged in fewer verbal interactions and more self-play than the TD group. Regarding physiological arousal, children with ASD as a group showed relatively higher cortisol in response to social play; however, there was a broad range of responses. Moreover, those with the highest cortisol levels engaged in less social communication. == Conclusions == The social interaction of children with ASD can be facilitated by peer solicitation; however, it may be accompanied by increased stress. The children with ASD that have the highest level of cortisol show less social motivation; yet, it is unclear if it reflects an underlying state of heightened arousal or enhanced reactivity to social engagement, or both. Keywords:Autism, cortisol, play, stress, social, interaction, behavior == INTRODUCTION == It has been proposed that deficits in social motivation are fundamental to nearly all children with autism spectrum disorder (ASD; (Chevallier, Kohls, Troiani, Brodkin, & Schultz, 2012)) and that poor social cognition (Baron-Cohen, 1995) is considered consequential (not causal). While this notion is appealing in that it provides a framework for the deficits in social orienting, Didanosine seeking, and maintaining behavior, it does not consider the substantial portion of children with ASD that demonstrate clear social interest and motivation. The characterization of autism as aspectrumdisorder has a long history (Kanner, 1943;Wing & Gould, 1979). Moreover, children with ASD are heterogeneous across biological parameters including social (oxytocin) Didanosine and stress (cortisol) hormones that may impact social functioning (Corbett, Schupp, Simon, Ryan, & Mendoza, 2010;Modahl et al., 1998). Finally, despite changes in diagnostic classification (APA, 2013), the domains of functioning remain diverse; therefore, the examination of phenotypic biobehavioral profiles, including motivational tendencies with peers, may reveal differences in the developmental trajectory of children with ASD and serve as a valuable guide to more individualized treatment of social functioning. The rudiments of social skills are acquired through observational learning Didanosine (Bandura, 1986) and a fundamental component is the motivation to engage in the observed behavior. Play is a primary training ground for children (Piaget & Inhelder, 1969;Vygotsky, 1978), facilitating the development of a variety of cognitive, motor, and social skills (Pellegrini & Smith, 1998). However, if a child fails to engage in these rudimentary activities with peers (Boucher & Wolfberg, 2003) a variety of age-appropriate perceptual, expressive, imaginative and problem-solving skills may not adequately develop. Subsequently, children with ASD seldom engage in spontaneous, age-appropriate play (Honey, Leekam, Turner, & McConachie, 2007;Yuill, Strieth, Roake, Aspden, & Todd, 2007) and Eno2 many show a preference for self-play rather than interacting with peers (Humphrey & Symes, 2011). When children with ASD do interact with peers, many experience increased anxiety (Bellini, 2006) and stress (Corbett, et al., 2010;Lopata, Volker, Putnam, Thomeer, & Nida, 2008). Additionally, children with ASD often do not form interpersonal relationships with peers (Krasny, Williams, Provencal, & Ozonoff, 2003) and are frequently subjected to ridicule and rejection (Church, Alisanski, & Amanullah, 2000). These negative experiences and increased insight into their limitations in social competence (Knott, Dunlop, & Mackay, 2006) may exacerbate social anxiety and stress especially with peers (Bellini, 2006;Schupp, Simon, & Corbett, 2013;White, Oswald, Ollendick, & Scahill, 2009). The hypothalamic-pituitary-adrenal (HPA) axis regulates many bodily processes and interactions, including reactions to psychological stress (Herman & Cullinan, 1997). The primary stress hormone in humans, cortisol, is secreted from the adrenal cortices in response to stress (Hennessey & Levine, 1979;Herman & Cullinan, 1997). Regarding psychosocial stress, Didanosine context, insight, and a perceived sense of threat mediates stress responsivity (Dickerson & Kemeny, 2004;J. W. Mason, 1968). Many children with ASD show higher cortisol when socially interacting with unfamiliar peers during play conditions (Corbett, et al., 2010;Lopata, et al., 2008); yet, they do not activate the HPA axis during a social performance-based task that reliably increases cortisol in typically developing children e.g., (Corbett, Schupp, & Lanni, 2012;Lanni, Schupp, Simon, & Corbett, 2012). Importantly, considerable variability in stress responsivity is evident in this heterogeneous disorder (Lopata, et al., 2008;Schupp, et al., 2013). Thus, an enriched understanding of the biobehavioral profiles of social stress in ASD is warranted. One way to explore the social world of children with ASD is to study them in natural social situations; namely, during play. Indeed, the study of play during natural contexts using careful, unobtrusive observation can.
