ing things has been explored in infancy and early childhood using a number of methodologies (Bullock, Gelman, and Baillargeon, 1982; Gelman and Gottfried, 1996; National Research Council, 2007; Springer and Keil, 1991). It is evident from this work that many of children’s earliest ideas about the natural world seem to focus on a distinction between social, intentional creatures as distinct from nonintentional, inanimate things (Carey, 1985). Indeed, it takes many years for children to accept plants as living things (Waxman, 2005).
Laboratory studies of children’s inferences about living things first suggested that they think about animals in terms of their relation to people (Carey, 1985). When told that people have a particular organ (e.g., a spleen) and asked whether a series of animals have that organ, children as old as 7 years often seemed to make decisions based on how similar the animal was to humans; a monkey would be judged as more likely to have the organ than would a butterfly, for example. Such findings were taken to suggest that children did not have a “naïve theory” of biology, but rather thought in terms of a “naïve psychology” with humans as the prototype. Later studies, however, have shown that Carey’s sample of mostly urban majority children reason differently on this task than do children from communities with more firsthand experience with nature. Both rural American Indian children from the Menominee community and rural majority children made inferences that indicate reasoning about biological kinds without anthropomorphism (Ross, Medin, Coley, and Atran, 2003). Furthermore, Tarlowski (2006) found that children whose parents are expert biologists were more likely to reason about animals in terms of biological categories, and Inagaki and Hatano (1996) found that children who had experience raising goldfish were more likely to reason in terms of biology than those who had not.
Research on children’s understanding of evolution has also revealed some interesting influences of learning about biology in families. Evans (2001, 2005) found some ways that developmental phases in understanding the origin of species are similar for children from different family backgrounds. She finds that many young children give “creationist” explanations, and then, as they get older, their families’ beliefs seem to influence children from fundamentalist and nonfundamentalist households to differentiate their beliefs about evolution.
These findings demonstrate that while there are trends related to age, children’s particular experiences, including cultural experiences outside school, are likely to have impact on their thinking about the domain of living things. Less is known about precisely how specific experiences actually affect their thinking. What does seems clear, however, is that much of this learning occurs in informal settings, and that it is likely to involve conversations with peers (Howe, McWilliam, and Cross, 2005; Howe, Tolmie, and Rodgers, 1992; Lumpe, 1995), parents, and other important people in children’s lives (Jipson and Gelman, 2007; Waxman and Medin, 2007).
Children’s understanding of the shape of the earth is another area in