When people are grumpy and irritable, we have a tendency to say that they woke up on the wrong side of the bed that morning. More likely, they woke up with too few hours of sleep under their belt. When we're tired, we're often moody and irritable. We may be short and snippy with those we care about the most. In this way, a lack of sleep can seriously stress our personal relationships, which is a pretty big deal when you consider the important role social networks play in determining our happiness.
In 2007, researchers examined just what's happening in sleep-deprived brains that might make us so grouchy. While a control group was allowed to sleep through the night, another group of subjects was kept awake for about a day and a half. Then both groups were shown images while their brain was monitored via functional magnetic resonance imaging (fMRI). Some of the images were extremely ordinary, such as pictures of a spoon, but gradually the pictures became more and more disturbing; at one point, the subjects were shown shark attacks and mutilated bodies.
When the sleep-deprived group was shown the gory images, the emotional centers in their brains became 60 percent more active than the control group's [source: Choi]. That large amount of difference between the groups surprised even the researchers, who posited that the prefrontal cortex, which helps to keep our emotions in check, wasn't able to send out inhibiting signals regarding emotions in the sleep-deprived. Without sleep, our emotions can run wild, but you're not likely to get happy out of an all-nighter; rather, the emotional centers that were activated were those connected to depression [source: Jayson].
You don't need an fMRI to know that being tired can leave you so frazzled that you can't enjoy life properly, though. So to ensure maximum levels of happiness, get enough sleep each night (seven and a half hours is recommended for most adults). If you have problems sleeping, try these tips:
- Avoid caffeine, alcohol, excessive liquids and large meals in the hours before bedtime.
- Get regular exercise, but schedule your workouts so that they're a few hours before you hit the hay.
- Set a regular sleep schedule and stick to it, even on the weekends, when you might be tempted to hit snooze.
- Use your bed only for sleeping, not for playing on the computer or watching movies. This helps your body and mind to know that when you're in bed, it's time to sleep.
For more on the things of life that can make you happy, see the links on the next page.