An explanation for this came from a genetic study at the Sleep and Performance Research Centre at Washington State University. Researchers there discovered that small parts of the brain send signals to the body that synchronize the time of day. This biological clock runs two hours ahead in morning people, and two hours behind in evening people. Evening people, therefore, become most effective later in the day. It is unclear, however, how our biological clocks make us more creative or emotional. Nobody has discovered if people are more creative and emotional because they stay up late. Or perhaps they stay up late because they are too emotional or creative to sleep.