A study just published by the journal Economics and Human Biology has demonstrated that the length of a person’s fingers — in relation to their other fingers — can function as a predictor of one’s salary. And it’s all determined before birth.

Scientists have long noted that certain predictors of success and skill level are correlated to if a person’s ring finger is longer than their index finger. Called the 2D:4D ratio, the length of the ring finger in relationship to the length of the index finger is a result of how many male hormones, mostly testosterone, a fetus is exposed to in the womb. The longer the ring finger, the more male hormones one was exposed to.

Previous research has found that the 2D:4D ratio can predict whether or not a person will be a good athlete, and a separate study done at the University of Cambridge found that the longer ring finger was correlated to success as financial traders in men.

Gender differences in the digit ratio are common. Men generally have longer ring fingers proportionally than women. In the new study, men and women between the ages of 25 and 60 in Russia were the focus. The longer the ring finger in proportion to the index finger, the researchers found, the higher a person’s salary was likely to be. This was true for both men and women, but more so for men than women. All of this correlates with previous research done on the 2D:4D ratio.

Effects of the ratio are not uniformly positive: People with shorter ring fingers have been found to have higher levels of anxiety, while men with longer ring fingers have been found to be more aggressive.