With Friends Like These

What could be more pure than true friendship? Actually, how we handle close company is anything but simple. Consider these foul undercurrents that run beneath the surface of camaraderie.

Prioritized Protection

Whether you realize it or not, the biggest factor in how you rank your friends is how you think they would rank you. Predicting who would take your side when push comes to shove trumps other traits you look for in a buddy.

Wingman's Revenge

Nearly everyone feels a ping of delight in their pals' misfortunes. The joy is greatest when a friend's dating prospects are hampered (gaining weight, tripping at a bar), since it means reduced competition for mates.

The Hand of Fate

Kids find people touched by luck more likable. We shun people who suffer disadvantages beyond their control—which may contribute to the persistence of social inequality.

From Benefits To Baggage

Most college kids say that hooking up with a friend enhanced their friendship, but be careful: In one study, failed romances caused almost a fifth of breakups between opposite-sex friends.

Bully Allure

While those who are agreeable, sympathetic, and compromising make great friends, kids still prefer to chum with those who are both prosocial and coercive. The draw? Resource control. It's tough to resist the sociable bully with unlimited dibs on the swing-set.

Et Tu, Brute?

We save the worst punishment for our friends. Betrayal by someone in your inner circle draws more flak than bad behavior from a stranger, because we use penalties to promote in-group cooperation.

New Friends Get Old

The dampened appreciation of novelty that can occur late in life also applies to friendships: Seventy-year-olds are less excited about making new friends than kids in their 20s.