photo of how many hours of sleep

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It May Stop You From Bringing Mr. Handsome Home
Look at something cute—like bunnies and ice cream sundaes (or perhaps any guy in a baseball cap). If you have underslept, you may respond more positively than usual (even giddily), as sleepless volunteers did in an fMRI study at UC Berkeley and Harvard. Sleep deprivation spikes the hormone dopamine, which excites the brain's reward-motivation-and-sex-drive-related pathways, and suppresses the "rational" prefrontal cortex. The result: risky, over-optimistic, impetuous decisions. (Mix sleepiness with alcohol and you’re also likelier to drink more than you otherwise would.)