Another day, another Trump retweet that attacks a woman. It’s not news. It’s no longer surprising to hear him attack women online. But according to social science, it does show his deep-seated insecurity.

Women’s Health Magazine reported about a new study in 2015:

According to the study, men with low self-esteem may be more likely to attack women online than men who feel good about themselves. (Shocking, we know…)

To conduct the study, researchers had 163 groups of men and women play a video game against each other. The only thing they knew about the other players was their gender. When the men performed poorly, their attitudes toward the other men playing stayed the same—but they started saying nasty things to and about the female players.

[…]

[M]en who feel good about their performance don’t necessarily feel the need to lash out. “Higher-skilled (i.e., more dominant) males do not behave in this manner, as there is no need for them to reinforce their dominance to maintain their attractiveness,” the authors state in the study.

As TIME put it: “Men who attack women online are actual losers.”

So there you have it.

AP Photo/Paul Sancya