Thinking you can catch mental illness: how beliefs about membership attainment and category structure influence interactions with mental health category members.

We explored beliefs about mental disorder categories that influence potential interactions with category members. Specifically, we investigated beliefs related to how membership in a mental disorder category is obtained (communicability and causal origin) as well as beliefs related to the underlying reality of disorder categories (essentialism and controllability). In Experiment 1, participants' interaction-willingness decisions were predicted by their beliefs that a mental disorder category was (1) communicable, (2) psychologically caused, (3) environmentally caused, and (4) possessed all-or-none membership. With fictitious mental disorders, people were less willing to interact with people described as having a communicable mental disorder than with those described as possessing any of the other factors of interest, highlighting the independent influence of these contagion beliefs (Experiment 2). We further explored beliefs about the communicability of mental disorders in Experiment 3 by asking participants to generate descriptions of how mental disorders are transferred between people. Our findings suggest the importance of understanding contagion beliefs in discovering why people distance themselves from people diagnosed with mental disorders. More generally, our findings help in understanding how our basic category knowledge is used to guide interactions with category members, illustrating how knowledge is translated into action.