A new study from the University of Durham suggests that traditional gender roles regarding income may still impact relationship dynamics. Researchers found that men experience lower levels of happiness and increased risk of mental health issues when their wives earn more than they do.

The study, published in The Economic Journal, analyzed data from heterosexual couples in Sweden who married in 2021. Researchers tracked these couples over a ten-year period, examining the relationship between income and mental health.

While the study found that both partners’ mental health was positively associated with their own and their spouse’s absolute income, it revealed a negative correlation when the wife’s income surpassed the husband’s. Specifically, the likelihood of a mental health diagnosis increased by 8% overall when the wife became the primary earner, with an 11% increase specifically for men. Among men, these diagnoses were often substance-related, while women were more likely to experience neurotic and stress-related disorders.

This finding is particularly relevant given the increasing number of couples globally where the wife earns more. Researchers noted that this trend has increased by approximately 25% since the start of the millennium in both the United States and Sweden.

The researchers suggest that this phenomenon may be linked to ingrained societal expectations about male breadwinner roles, even in countries like Sweden that promote gender equality. While the study didn’t explore the reasons behind the findings in detail, lead researcher Demid Getik suggested that established preferences for men to be the higher earner likely play a role. He noted that the data didn’t provide insights into individual perceptions and attitudes.

The study highlights the potential impact of relative income within couples on mental health, even in societies that strive for gender parity.