You probably already know that being sleep-deprived will make you cranky. But as this new Happify infographic explains, going without a good night's sleep can change your personality in some more unexpected ways, too.It's tough to think positively about a new day when the night before wasn't great. In a study published earlier this year, researchers found that participants fell prey to repetitive negative thought patterns much more easily when they hadn't gotten enough sleep. Also, if you have a genetic risk for depression, you're more likely to actually experience symptoms when you've gotten fewer than seven hours (or, interestingly, more than the recommended nine). study published in 2006 in the journal Sleep examined how being sleep-deprived for nearly 50 hours affected participants' abilities to find cartoons and silly headlines funny. Without sleep, nothing was quite as entertaining. The researchers also found that, while caffeine made participants feel less tired, only modafinil — a — helped them find cartoons amusing.

3. It's harder to feel gratitude.

In a study presented at the annual meeting of the Society for Personality and Social Psychology in 2013, researchers asked participants to list five things they were grateful for — and then to rate their own gratitude. Those who hadn't gotten a full night's sleep didn't feel as grateful as those who were well-rested. Another experiment in the same study found that people felt more gratitude over a two-week period when they got more sleep — and they were more selfish when they hadn't gotten as much shut-eye.So basically, without sleep, the world is less nice to you, and you're less nice to be around. Check out the full infographic below to find out more about how sleep affects your happiness.