Research suggests that for adults, “folkpsychology” and “folkbiology” represent distinct conceptual domains for reasoning about living things. However, it is not clear whether these domains are distinct for children; past work suggests that the 2 systems are confused until age 10, and that radical theory change accounts for eventual differentiation. To examine this claim, 16 subjects each at ages 6, 8, and adult were shown pictures of predatory and domestic animals and asked whether each animal displayed a variety of biological properties (e.g., has blood) and psychological properties (e.g., can think, can feel angry). Subjects at all ages showed clearly different attribution patterns for biological versus psychological properties. This dissociation of attribution patterns provides evidence that by kindergarten, notions of folkpsychology and folkbiology are sufficiently differentiated to constitute distinct and independent conceptual domains. This in turn suggests that radical theory change regarding living things either occurs prior to the beginning of formal education, or does not explain the development of folkbiological knowledge.