“…A total of 28 studies published between 1994 and 2007, comprising k = 34 independent samples, were identifi ed by the search strategy, met the inclusion criteria, and contributed to the metaanalysis ( Bierut et al, 2000 ;Comings et al, 1996Comings et al, , 1997Connor et al, 2007 ;Costa-Mallen et al, 2000 ;David et al, 2007 ;Erblich, Lerman, Self, Diaz, & Bovbjerg, 2004Freire, Marques, Hutz, & Bau, 2006 ;Hamajima et al, 2002 ;Johnstone, Yudkin, Griffi ths, et al, 2004 ;Lee, 2003 ;Lerman et al, 1999Lerman et al, , 2003Morton et al, 2006 ;Noble et al, 1994 ;Preuss, Zill, Koller, Bondy, & Sokya, 2007 ;Qi, Tan, Xing, Miao, & Lin, 2002 ;Robinson et al, 2006 ;Sabol et al, 1999 ;Singleton et al, 1998 ;Spitz et al, 1998 ;Swan et al, 2005 ;Timberlake et al, 2007 ;Ton et al, 2007 ;Wu, Hudmon, Detry, Chamberlain, & Spitz, 2000 ;Yoshida et al, 2001 ). Data from the present study also were included in the meta-analysis.…”