Running head: SOCIAL ORIENTING AND JOINT ATTENTION SKILLS

From the moment infants are born, they seem to prefer orienting to social stimuli, over objects and nonsocial stimuli. This preference lasts throughout adulthood and is believed to play a crucial role in social-communicative development. By following up a group of infants at the age of 6, 8, and 12 months, this study explored the role of social orienting in the early development of joint attention skills. The expected association between social orienting and joint attention was partially confirmed. Social orienting in real life photographs of everyday situations was not related to later joint attention skills, however fixation to the eyes in a neutral face was related to response to joint attention skills, and fixation to the eyes in a dynamic video clip of a talking person was predictive of initiating joint attention skills. Several alternative interpretations of the results are discussed. SOCIAL ORIENTING AND JOINT ATTENTION SKILLS 2 From the first moment infants start to visually take in the world, they seem to prefer looking at other people, more than to other stimuli in the environment. Numerous studies have demonstrated that infants are showing an innate preference to orient to all sorts of social stimuli, such as faces, eyes, and voices (e.g., Cassia, Valenza, Simion, & Leo, 2008; Farroni et al., 2005; Lozonczy, 2004; Morton & Johnson, 1991). This tendency to orient to social stimuli is believed to be very important in social development, and it is demonstrated to last throughout life (e.g., Fletcher-Watson, Leekam, Benson, & Findlay, 2009). The explanation for this tendency has, amongst others, been searched for in studies on early visual processes (e.g., Farroni et al., 2005; Frank, Vul, & Johnson, 2009; Simion, Leo, Turati, Valenza, & Barba, 2007). There is for example some support for a link between contrast sensitivity and the preference to look at faces (Farroni et al., 2005). Neurological evidence has been found for the involvement of an early magnocellular system that is sensitive to low spatial frequency stimuli and luminance contrast. This system influences early visual experience, leading infants to orient to social stimuli (Plaisted & Davis, 2005). In addition, social stimuli are believed to have an inherent positive rewarding value through the development of a specific motivational system (Mundy & Sigman, 2006) mediated by neural mechanisms. In many studies, social orienting has been investigated as the orientation of attention in response to a social cue (e.g., following the eye gaze of another person, responding to name calling). However, in this study, the approach of Birmingham and Kingstone (2009) is followed, who propose that the study of the selection of the cue (orienting to social stimuli) is as important as the reaction to the cue itself. After all, if infants do not actively orient towards social stimuli in the first place, they are not able to pick up the meaning of social cues and will fail to respond appropriately when confronted with one. SOCIAL ORIENTING AND JOINT ATTENTION SKILLS 3 Social orienting is expected to be related to social-communicative skills, such as joint attention, which involves the triadic coordination between the infant, another person, and an object or event (Adamson, 1995; Mundy, Sigman, & Kasari, 1994). These triadic interactions, with a developmental start very early in life and clearly present around the age of 9 months (Bruinsma, Koegel, & Koegel, 2004, Striano & Bertin, 2005), are believed to build on earlier forms of dyadic engagements (Striano & Rochat, 1999). Active attention to social stimuli would therefore be a crucial step in this development, since it leads to more opportunities to engage in social interactions, in which children can learn about socialcommunicative skills. Moreover, the motivational system that leads to the rewarding value of social stimuli, is also believed to be the reason why children participate in triadic interactions. It seems plausible that the preference to orient socially could vary between children and that it has a predictive value for the development of social and communicative abilities, such as joint attention skills (Maestro et al., 2002). In children with social impairments, such as children with autism, a lacking tendency to orient towards social stimuli has been proposed as one explanation for their difficulties with joint attention skills (Maestro et al., 2005; Mundy & Burnette, 2005). Some studies have found support for this association (Dawson, Meltzoff, Osterling, Rinaldi, & Brown, 1998; Dawson et al., 2004). However, it must be noted that in these studies social orienting was defined as the attentive reaction towards a social cue, rather than the voluntary attention to social stimuli. In typical development, little is still known about the nature of individual differences in infants’ joint attention skills (Mundy et al., 2007; Mundy & Newell, 2007). The link between social orienting and joint attention has been suggested multiple times, but is seldom investigated in typical development. The social preference of young infants is irrefutably demonstrated, as is the pivotal role of joint attention in development. However, SOCIAL ORIENTING AND JOINT ATTENTION SKILLS 4 the association between them is yet to be understood. Therefore, this longitudinal study will try to shed some light on the role of social orienting in the development of joint attention, by following up a group of typically developing children at the ages of 6, 8, and 12 months. The focus will be on social orienting as a voluntary attentional process, measured in a precise way, with as high ecological validity as possible. An eye-tracking device is used to present photographs of real life situations, more detailed photographs of close up faces, and a video clip of a person talking to the child. In other studies, static and dynamic stimuli are seldom investigated together, sometimes leading to conflicting results, since both types of stimuli are assumed to be processed in a different way (Shaddy & Colombo, 2004; Lewcowicz, 2008). This study is one of the first to explore attention orienting towards different types of social stimuli in young infants, and to investigate the link with later joint attention skills. Response to joint attention skills are assessed at the ages of 8 and 12 months, and initiation of joint attention skills are assessed at the age of 12 months. The individual differences in both response to, and initiation of joint attention skills are expected to be predicted by the individual differences in social orienting at the age of 6 months.