It doesn't get much better than a night out with your friends. But for some of us, drinking brings out a different version of ourselves — one that's mean and reckless. And according to new research, your genes may be partly responsible for the way you handle your booze. For the study , published today in Translational Psychiatry, researchers looked at the personalities and drinking behaviors of two groups of Finnish participants. The first group consisted of 14 people (six women and eight men) with a particular genetic variation that had been identified in a previous study . The second group, a control group, consisted of 156 men who did not have that genetic variation. Results showed that participants with this particular genetic variation were more likely to act aggressively when under the influence of alcohol than those who didn't have the variation. For instance, they were more likely to report getting into fights while drunk, throwing tantrums, and being arrested for driving under the influence. People with the variation were also more likely to have high anxiety, be uncomfortable with uncertainty, and not be interested in exploring new things. These participants "were not alcoholics per se, as measured by average alcohol consumption, and were not diagnosed as alcoholics," the study authors write, "but they had a tendency to lose behavioral control while under the influence of alcohol." The variation in question is located on the gene that codes one type of serotonin receptor in your brain. In previous research, participants in Finland with this variation were shown to be more impulsive on average. So it makes sense that those participants would be even more impulsive when drinking. There are a few obvious weaknesses of the study, however. For one, the groups were small and made up almost entirely of men. Although there weren't any major gender differences in the study, these might be difficult to see with so few women involved. And of course, there are factors beyond your genetics that influence the way you act, regardless of whether you're drunk. But your genes play a bigger role in your drinking than you might realize. For instance, having a particular variation of a gene may make one of our alcohol-digesting enzymes more efficient at its job. Therefore, we might be more likely to indulge in that second brunch-time bloody mary. The bottom line: Know what your own patterns are — and when it might be smart to call it a night.