A new study sheds light on how other people influence our mind. Research on mice, whose brains are remarkably similar to humans, reveals that our brains are affected by those around us. The key factor is dominance. The brain of the subordinate mouse synchronized to the dominant mouse. This likely applies to our relationships. Typically, people with stronger personalities make the decisions and get their needs met more often than their partners do.

Other factors play a part. The more the mice interacted with each other, the more their brain activity was synched. Hence, the longevity and intensity of a relationship affect the degree to which those close to us have influence. A further twist on brain synchrony turns on two types of brain cells. One set is focused on our own behavior, and a second set focuses on other people.