the most measures. In order to test whether effect sizes differ for broad or narrow measurement of personality, we included studies that used the same data but reported the results at different levels of trait generality (e.g., Blonigen, Carlson, Hicks, Kreuger, & Iacono, 2008; Hopwood, Donnellan, Blonigen, Krueger, McGue, Iacono, & Burt, 2011). Our final sample of studies included 24 longitudinal twin-sibling studies from 21 unique samples comprising 21,057 sibling pairs. The sibling pairs included 7,787 monozygotic reared together twins, 12,951 dizygotic reared together twins, 59 monozygotic reared apart twins, 156 dizygotic reared apart twins, 60 half-siblings reared together, and 44 biologically unrelated siblings reared together. Table 1 presents the citation, dataset, age ranges, measures and sample size of each article. Raw or model implied group within- and across-time correlations were extracted from each article for each pair of time points and repeated measures.4
