Pick who you work with very carefully. Because you are likely to become like them. So the first thing is to know what's important to you about you — what you want to become. What you like about yourself. And then, surround yourself with people who match your aspirations for yourself.

Here are some ideas:

Choose people who are good-looking, but not better looking than you.
You become like the people you hang out with, according to Nicholas Christakis, a physician and sociologist at Harvard. He found, for example, that if the people around you are overweight, you are likely to join them. And the more overweight you are, the more trouble you have at work, for a lot of reasons, but a new reason I just found is that in stressful work situations, fat people do not think as clearly as thin people. Yep. That's right. Stonybrook University School of Medicine found that the more body fat you have, the higher your levels of cortisol, a stress hormone that hampers cognitive abilities. (Hat tip: Self magazine.)

But if the people around you are models, you will look ugly. Dan Ariely, professor of behavioral economics at MIT, says that if you're going to a bar, you have the best chances of getting picked up if you go with people who are almost as good-looking as you are. It makes sense that you will feel best if you do this at work as well.

Choose women who are happy, but they shouldn’t smile too easily.
This is hard for men to do. Because men are hard-wired to be drawn to women who laugh at their jokes. Men want to be funny. But women who are slower to smile do better at work, according to communications consultant Leil Lowndes. So you should date women who smile a lot, but work with women who don't. (Hat tip: Derek Scruggs.)

But this doesn't mean that you should work with grouchy women. Christakis also found that if you are around happy people you will be happier. So, when it comes to work, find that subset of women who are very optimistic but a tough audience for your jokes.

Choose people who swear, but don't choose someone who’s trashy.
It turns out that a little off-color language is good for the workplace. For example, if you use not-too-vulgar swear words at work, you inspire more teamwork. Of course, the standards for vulgarity will vary, but it's probably like porn: You know it when you see it.

Which is why using something innocuous, like the word asshole, is okay, but not if you are talking about intercourse. People who talk about sex at work decrease morale. Well, the research actually says that it's the raunchiness of the sex talk that affects the workplace negatively. So I think factual talk about sex, without the raunch, is okay. (Hat tip: Chris Yeh)

Also, while we're on the topic: double-bonus for choosing a boss: Pick one that will send you to sex conferences.

Choose people you admire.
This seems like a no-brainer, but we rarely choose a job based on this. We usually choose a job based on the job description, or the title. The problem with choosing a job this way is that a job description is not a contract. It is a way to lure you into the job. And it's a hiring manager's best guess on who he or she is looking for. In general, we do not end up doing what we are hired for.

So choose your next job based on the people you'll be working with. You will learn the most on a job by having a great mentor looking after you, rather than a good job description preceding you. And you'll be happiest at work if you focus on having friends at work instead of looking for a boss who pays high salaries — those bosses don't understand what really matters.

The problem, of course, with choosing to work with people you admire is that you have to understand yourself enough to know, of all the traits you admire in people, what are the most important.