Let’s face it. Not everyone puts in the effort to get the job done, whether at work or in life. In order to understand why motivation varies among people, researchers looked at how the brain chemical dopamine differed between slackers and hard workers. In a recent study, published in the Journal of Neuroscience, volunteers completed a series of difficult and easy tasks on a keyboard. They were also rewarded for their efforts—from $1 to $4 for harder tasks, such as hitting a button 30 times in seven seconds. As in the workplace, some people put in more effort than others. The hardest workers showed higher levels of dopamine in two areas of the brain related to reward and motivation. Dopamine is a neurotransmitter in the brain that was once known as the “pleasure chemical.” Scientists now know that it plays important roles in motivation and reward, as well as voluntary movement and behavior. The volunteers who gave up more easily also showed higher levels of dopamine in their brains, but in an area related to emotion and risk perception. Researchers say that while the harder workers were more focused on the reward, the others tended to think about the costs—“how tired their pinky was.” These differences are related to the varying levels of dopamine in different areas of the brain. Far from giving a free pass to slackers, this research may help scientists develop better treatments for conditions that involve decreased motivation, like depression and attention deficit hyperactivity disorder (ADHD). Natural variations in dopamine levels can affect how people respond to medications for these disorders.