Young Adults Make Rational Sexual Decisions.

We examined risky sexual choice under the lens of rational decision-making. Participants (N = 257) completed a novel sexual-choice task in which they selected from among hypothetical sexual partners varying in physical attractiveness and in the probability that one would contract a sexually transmitted infection (STI) from a one-time sexual encounter with them. We found that nearly all participants evaluated the sexual-choice alternatives in a coherent fashion consistent with utility-based theories of rational choice. In subsequent analyses, we classified participants' responses according to whether their sexual preferences were based on maximizing attractiveness or minimizing the risk of STIs. Finally, we established an association between sexual choice in our task and reported real-world sexual risk-taking.