“…Piagetian clinical interviews have shown that North American children do not come to understand human reproduction until late in the elementary school years (e.g., Bernstein & Cowan, 1975). Although it has been argued that these interviews underestimate preschool children's understanding (Atran, 1998;Hirschfeld, 1996;Solomon, Johnson, Zaitchik, & Carey, 1996;Springer & Keil, 1989;Wellman & Gelman, 1998), it is not clear that young children perform any better in switched-at-birth and adoption studies, which ask children to reason about the resemblance between offspring and their birth or adoptive parents and which do not require them to explicitly articulate their understanding of innate potential and of the role of birth parentage in the inheritance of properties (e.g., Arterberry, Barrett, & Hudspeth, 1999;Carey, 1995;Gimenez & Harris, 2002;Solomon, 2002;Solomon et al, 1996;Weissman & Kalish, 1999;Williams & Affleck, 1999). Indeed, the interpretation of these studies is under active debate.…”