By watching sore spouses bicker, researchers have noticed a pattern of gender differences. Insecure men tend to focus on fears of their partner’s sexual infidelity. Inflamed with jealousy even when there’s no cause for it, they become highly possessive and controlling, which puts stress on the relationship and eventually drives the woman away. Insecure women worry less about sexual infidelity than about other kinds of rejection, and they tend to react with hostility rather than jealousy. These reactions were cataloged in a study of New York City couples who were videotaped in a lab at Columbia University as they discussed their problems.

Each time one of the partners did something negative— complaining, speaking in a hostile tone, rolling their eyes, denying responsibility, insulting the other—the action was classified and counted. The researchers, led by Geraldine Downey, found that insecure people were the ones most likely to act negatively. Their own fear of rejection no doubt intensified the distress they felt, because for them an argument wasn’t just about a specific issue but a sign of deep problems and an ominous signal that the relationship was in jeopardy. Their panicky response was to push away their partner—with unfortunate success, as the researchers found by following couples over several years. People sensitive to rejection were especially likely to end up alone. Their fear of rejection became a self‑fulfilling prophecy.