When it comes to the amount of psychological distress experienced by men, new research suggests men are the most psychologically distressed when they are entirely economically dependent on their wives.

The study, conducted by the Society for Personality and Social Psychology, found men’s stress level to be significantly U-shaped when it comes to household earners. Stress is also high when the man is the sole breadwinner; however, men are least distressed when their wives bring in 40% of household income.

The results, study author Joanna Syrda writes, “reflect the stress associated with being the sole breadwinner, and more significantly, with gender norm deviance due to husbands being outearned by their wives.”

In 1970, only 4% of women outearned their husbands; according to Bureau of Labor Statistics numbers from 2015. Today, 38% of women outearn their husbands.

The research also found patterns in women’s stress levels to be less U-shaped than men. You can find the full report online.