Can we get sick if we want to? Children's and adults' recognition of intentionality in the origins of illness and injuries.

The present set of studies examined the impact of intentionality (wanting/not wanting to get sick) on the transmission of contagious illness and injuries. Study I examined whether preschoolers and adults thought that a recipient of an illness is more likely to get sick if he/she wanted to. Studies 2, 2a, and 3 examined if the intentions of the transmitter would influence the transmission of illness to the recipient. Study 4 examined the influence of germs on intentionality. Both preschoolers and adults reasoned that the intentions of the recipient would play a significant role in the probability of contracting an illness but only adults reasoned that the recipient having knowledge of the transmitter's intentions would have an impact on illness. Moreover, preschoolers (but not adults) judged that biological contaminants such as germs would interact with the intentionality of the recipient to increase the chances of contracting an illness whereas adults reasoned that psychological states can have a direct influence on the manifestation of illness. These results suggest that preschoolers and adults entertain a highly sophisticated and selective process when assessing, the impact of psychological factors such as intentionality on biological processes such as the origins of illness. [ABSTRACT FROM AUTHOR]