Besides systematic changes of alcohol involvement, a number of other developmental changes appear to occur during emerging and young adulthood. Though personality traits have traditionally been posited as intrinsic and unchanging internal dispositions (McCrae et al., 2000; but see also Costa & McCrae, 2006), more recent perspectives have begun to view personality traits as dynamic constructs that change systematically over the life course (e.g., Johnson, Hicks, McGue, & Iacono, 2007; Roberts, Caspi, & Moffitt, 2003). A burgeoning collection of cross-sectional and longitudinal studies have documented systematic patterns of mean-level changes in personality traits at various ages across the life span, including during emerging and young adulthood (Caspi, Roberts, & Shiner, 2005; McCrae et al., 1999; Roberts, Walton, & Viechtbauer, 2006). A recent meta-analysis (Roberts et al., 2006) found a clear pattern of normative change across the life course, with people becoming more socially dominant, conscientious, and emotionally stable with age. Consistent with other findings (e.g., Roberts, Caspi, & Moffit, 2001), Roberts and colleagues (2006) found that personality traits changed more during emerging and young adulthood than during any other period of the life course, including adolescence.
