Gunning for a raise or promotion? Better start making nice with your coworkers.

People who initiate friendships at work, offer their colleagues help and engage with office mates at social events are 40 percent more likely to get a promotion, according to a 2011 study by Shawn Achor, a lecturer on psychology at Harvard University and author of The Happiness Advantage: The Seven Principles of Positive Psychology That Fuel Success and Performance at Work.

While skills, experience and results delivered are obviously factors in career advancement, one’s likeability is also a key component of workplace success. If you’re too competitive (or too much of a brown-noser), you can alienate the very coworkers who could be crucial to your success. After all, bosses don’t want to promote people who are disliked around the office. Even if you’re not hanging out during non-office hours, you’re probably spending more time with your colleagues than with your non-work pals. So building relationships may be one reason that 30 percent of those polled by Monster said that friendships make work a lot more pleasant.

Click here to see what steps to take to win over your boss and your colleagues.