Social Behavior: Several lines of research are consistent with small sex differences in emerging personality and social domains. A metaanalyses of gender differences in temperament found that, compared to boys, infant girls are better able to inhibit responses and show greater sensitivity to environmental changes, greater fearfulness, and lower activity levels (ElseQuest, Hyde, Goldsmith, & Van Hulle, 2006). Infant girls may also show greater responsiveness to social stimuli, such as the maternal face, sound, or touch. For example, compared to males, female newborns score higher in global ratings of cuddliness (Benenson et al., 1999), show more orientation to a face or voice (Connellan, Baron-Cohen, Wheelwright, Batki, & Ahluwalia, 2000; Osofsky & O’Connell, 1977), and, like older infant girls (Mundy et al., 2007), exhibit longer eye contact with an experimenter (Hittelman & Dickes, 1979). Sex differences in the incentive value of social stimuli are also consistent with findings that infant girls show stronger visual preferences for a doll (i.e., an object with human attributes) than for a toy truck (Alexander, Wilcox, & Woods, 2009) than infant boys. In contrast, boys shortly after birth show stronger visual preferences for a mechanical mobile than for a face (Connellan et al., 2000) and, like much older boys, in the 1st year of life they show more visual preferences for balls, vehicles, and a group of figures than for a solitary figure (Alexander et al., 2009; Benenson, Duggan, & Markovits, 2004; Campbell, Shirley, & Heywood, 2000).