The understanding that people can own certain things is essential for activities such as trading, lending, sharing, and use of currency. In two studies, children in grades K, 2, and 4 ( = 118) and adults ( = 40) were asked to identify whether four kinds of individuals could be owners: typical humans, non-human animals, artifacts, and atypical humans (e.g., individuals who were sleeping or unable to move). Participants in all age groups attributed ownership to typical humans most often, non-human animals less often, and artifacts least often. In a third study, children and adults ( = 240) attributed property rights to individuals who were awake, asleep, or tied up, but children continued to deny that these rights extend to atypical humans. Although both children and adults use an ontological boundary to guide their ownership attributions, concepts of owners change significantly over the course of development.

Authentic objects are those that have an historical link to a person, event, time, or place of some significance (e.g., original Picasso painting; gown worn by Princess Diana; your favorite baby blanket). The current study examines everyday beliefs about authentic objects, with three primary goals: to determine the scope of adults' evaluation of authentic objects, to examine such evaluation in two distinct cultural settings, and to determine whether a person's attachment history (i.e., whether or not they owned an attachment object as a child) predicts evaluation of authentic objects. We found that college students in the U.K. (N = 125) and U.S. (N = 119) consistently evaluate a broad range of authentic items as more valuable than matched control (inauthentic) objects, more desirable to keep, and more desirable to touch, though only non-personal authentic items were judged to be more appropriate for display in a museum. These patterns were remarkably similar across the two cultural contexts. Additionally, those who had an attachment object as a child evaluated objects more favorably, and in particular judged authentic objects to be more valuable. Altogether, these results demonstrate broad endorsement of "positive contagion" among college-educated adults.

The present study examined children's understanding of illness in a peri-urban community in South Africa where AIDS is prevalent (N = 138). Results suggest that children were surprisingly knowledgeable about AIDS at an early age, and may have even erroneously analogized from AIDS to the flu. Furthermore, all age groups attributed different causes for AIDS (transmitted by blood) and flu (casual contagion). However, although factual knowledge about AIDS was identified among all age groups, there was no evidence of understanding biological causal mechanisms. The data have implications both for developmental research on biological reasoning in diverse cultural contexts and for the design of health education programs.