We’re born to be tame. A new study reveals that human brains are more different from our great ape relatives than previously thought. It’s all about our control systems for dopamine, pleasure’s chemical trigger, and may explain why we behave so differently from our hairier cousins. Dopamine levels are thought to be linked to everything from memory and emotion to disorders like schizophrenia. One hypothesis researchers plan to test is that this control mechanism allows us to work toward far-from-instant gratification — like doctoral degrees in neuroscience.