Jealousy is a normal, common, and often terribly uncomfortable human emotion. With the rise of social media, there are new opportunities to become jealous around every corner. But it turns out that jealousy may not be the relationship killer we think it is—admitting jealous feelings could even strengthen a romantic bond.
Evolutionary psychologists think that jealousy is an evolutionary mechanism to help humans ward off "mate-poaching." A 2013 study in the Journal of Social and Personal Relationships that had couples keep diaries of their and their partners' temptations, their feelings of commitment, and any "mate-guarding" behaviors taken, and found that people could tell pretty accurately when their partner was tempted. At the same time, however, the couples reported feeling more committed to the relationship when they had taken measures to guard their sweetie from temptation.