The foam machine sputters and the bass bumps as the primates go out for their nightly romp. The two on the left look as if they’ve melted into one spasmodic being, banging their bodies against each other as if they’re trying to spark a fire.

They’re the bonobos.

The two on the right hoot up and down and stick out their paws as the guy in charge of the peppermint schnapps shots dishes out his wares.

They’re the chimps.

On college campuses across the country, students imitate their ape counterparts nightly, a scene surprising only in its regularity. It could be the ranch party at Kappa Alpha or the toga party at Chi Phi. On this night, it’s the foam party at Phi Delt. But the location or the theme — even one involving suds — is irrelevant.

These bonobos, these chimps, these great apes cloaked in their Burberry and Gucci, are unleashing their inner primate — LSATs, MCATs and GPAs be damned.

Frans de Waal hasn’t been to a Fraternity Row party. But he knows the scene. De Waal has devoted his life to studying great apes, a group of primates with DNA 98.5 percent identical to that of humans. In doing so, he has revolutionized the world of primatology and uncovered the building blocks of human behavior. This is in addition to authoring multiple bestselling books, earning a ranking as one of TIME Magazine’s 100 People Who Shape Our World and indulging in a passion for photography that has earned him considerable acclaim. He also cooks a mean Indian curry, according to his wife.