T he view of the mind as a Blank Slate, devoid of xed instincts and subject only to the inuence of experiences after birth, was eloquently championed by John B. Watson in 1925. That view, reinforced by reports of cultures seeming to violate most North American norms of conduct, strongly inuenced 20th-century psychology (see Pinker, 2002, for a review). Experimental research on learning and cognition, though, did not support the Blank Slate view. It turned out that even so simple a process as classical conditioning is biased to favor associations of the sort regularly confronted by a given species. Rats, for example, whose ancestors often searched for food in the dark, more easily condition aversions to new tastes than to visual cues. Quail, on the other hand, whose ancestors searched for food in broad daylight, condition nausea more easily to visual than to gustatory cues (Wilcoxon, Dragoin, & Kral, 1971). Further problems for a Blank Slate view came from research revealing cross-culturally consistent behavior patterns rather than innite malleability (e.g., Brown, 1991; Buss, 1989; Daly & Wilson, 1988; Kenrick & Keefe, 1992; Pinker, 1994).