The baby effect and young male syndrome: social influences on cooperative risk-taking in women and men

Parental investment theory predicts differences in risk-taking for females and males as a consequence of reproductive context, with females attempting to reduce risks in relation to their own offspring (here called the baby effect) and males taking more risks in competition with one another (young male syndrome). The experiment we report tests these predictions in a cooperative context by introducing the Social Balloon Analogue Risk Task—the Balloon Analogue Risk Task modified to include a social partner (adult male, adult female, or baby)—along with a commitment device in which participants choose among several possible social partners, with whom they will share their earnings. Results were consistent with the predictions of parental investment theory. Females did not change their levels of risk-taking when paired with adult males or females, but showed a strong reduction in risk when paired with babies. Consistent with previous research, males were strongly inclined to take more risks when paired with another male of the same age, but males showed no change in risk-taking when paired with a female of the same age or a child. The current work provides the first experimental evidence of gender differences in cooperative social risk-taking, as well as the first experimental evidence of a mediator of female risk-taking, i.e., babies.