“At one of my first jobs, I was blogging for an entertainment media company but was eager to take on extra script writing. Shortly after I was hired, another female writer came on board. My editors asked us who wanted to take on a new assignment, and I didn’t raise my hand. She landed the gig, and the next one too.

Now I realize why I held back—I was afraid our relationship would suffer. Anticipating a rift between us made me avoid competing with her altogether.

What I experienced is a real thing. Selin Kesebir, Ph.D., an assistant professor at London Business School, has studied how competition affects women’s relationships. Her team asked women and men to complete a simple typing task with same-gender and with opposite-­gender participants and rate how they felt afterward. The women going up against other women reported higher levels of negative emotions—like feeling nervous, insecure, or hesitant. Men competing with each other were more likely to report positive reactions; they felt energized and excited. And when the women went head-to-head with the guys? They didn’t feel as threatened as with their female peers, nor did they worry their relationships with the men would suffer. It was a girl-on-girl problem.”