“…In non-human species, exploratory or bold behavior may increases risk of predation (guppies: Dugatkin, 1992;Godin & Davis, 1995;theoretical model: Wolf, van Doorn, Leimar, & Weissing, 2007; for review, see Smith & Blumstein, 2008), and among humans, extraversion can similarly carry fitness-relevant costs -extraverts are disproportionately represented in hospitals with injury or illness (Nettle, 2005) and their pronounced sensation-seeking can lead to traumatic injury (Field & O'Keefe, 2004) and legal trouble (Ellis, 1987). Similarly, high levels of agreeableness can carry fitness costs; individuals who avoid conflict are less desirable as mates in a variety of species, including humans (e.g., fighting fish: Doutrelant & McGregor, 2000;Midas cichlid: Barlow, 1986;humans: Lukaszewski & Roney, 2011), and high agreeableness may lead individuals to forgo their own objectives and risk social exploitation (Judge, Livingston, & Hurst, 2011). Although high levels of neuroticism may cognitively and affectively motivate an individual to protect limited social opportunities, high neuroticism is associated with impaired somatic health (Cohen & Williamson, 1991;Glaser & Kiecolt-Glaser, 2005;Herbert & Cohen, 1993;O'Leary, 1990) and can place burdensome strain on social relationships (e.g., Buss, 1991a;Neeleman, Sytema, & Wadsworth, 2002).…”