The typical developmental trajectory of social and executive functions in late adolescence and early adulthood.

Executive functions and social cognition develop through childhood into adolescence/early adulthood and are important for adaptive goal-oriented behaviour (Apperly, Samson & Humphreys, 2009; Blakemore & Choudhury, 2006). These functions are attributed to frontal networks known to undergo protracted maturation into early adulthood (Barker, Andrade, Morton, Romanowski & Bowles, 2010; Lebel, Walker, Leemans, Phillips & Beaulieu, 2008) although social cognition functions are also associated with widely distributed networks. Previously, non-linear development has been reported around puberty on an emotion match to sample task (McGivern, Andersen, Byrd, Mutter & Reilly, 2002) and for IQ in mid adolescence (Ramsden et al., 2011). However, there are currently little data on the typical development of social and executive functions in late adolescence and early adulthood. In a cross sectional design, 98 participants completed tests of social cognition and executive function, Wechsler Abbreviated Scale of Intelligence (Wechsler, 1999), Positive and Negative Affect Scale (Watson, Clark & Tellegan, 1988), Hospital Anxiety and Depression Scale (Zigmond & Snaith, 1983) and measures of pubertal development and demographics at age 17, 18 and 19. Non-linear age differences for letter fluency and concept formation executive functions were found, with a trough in functional ability in 18 year olds compared to other groups. There were no age group differences on social cognition measures. Gender accounted for differences on one scale of concept formation, one dynamic social interaction scale and two empathy scales. The clinical, developmental and educational implications of these findings are discussed.