Women's successes at work deal a blow to their partner's self-esteem, making men more pessimistic about the longer-term prospects of their relationship, research has revealed.
While men did not admit to feelings of insecurity caused by their partners' successes, their feelings of negativity and inadequacy could be gauged through tests including word association and other experiments.
The negative impact could be seen even in cases where the couple were not in directly competing professions, according to a study published in the Journal of Personality and Social Psychology.
"There is an idea that women are allowed to bask in the reflected glory of her male partner, and to be the 'woman behind the successful man', but the reverse is not true for men," said the study's co-author, Kate Ratliff, of the University of Florida.
Ratliff and Shigehiro Oishi, a researcher at the University of Virginia, put participants through a series of experiments to gauge how their partner's success impacted on both sexes' mood, both spoken and unspoken.
In cases where a woman outperformed her male partner in social or intellectual tasks, men registered a dip in their implicit self-esteem. By contrast, women registered no negative emotions at their partners' achievements.
A partner's successes led women to feel more confident about the prospects for their relationship. But a partner's achievements would make men more pessimistic.
"Thinking of themselves as unsuccessful might trigger men's fears that their partner will ultimately leave them," the authors wrote.
The researchers proposed a "zero-sum" effect, in which a gain is offset by an equal loss, leading men to feel a sense of failure that fuelled a sense of resentment when their partners succeeded.
This led men to equate their partner's successes with their own failures, the study suggested.
"While it makes sense that Tom might feel threatened if his girlfriend Jane outperforms him, it is less clear how Tom would feel about himself if Jane succeeds when they are not in direct competition with one another," the authors wrote in their paper, entitled Gender Differences in Implicit Self-Esteem Following a Romantic Partner's Success or Failure.
"A partner's success could lead to a decrease in self-esteem (the 'zero-sum game hypothesis') if we interpret 'my partner is successful' as 'my partner is more successful than me'."
This research tested the influence of a partner's success or failure on the individual's own sense of self-esteem, both implicit and explicit.
One experiment found that men's implicit self-esteem was more dented when their partner did well at a "social intelligence" task than when their partner did poorly. Women's implicit self-esteem was unaffected by their partner's performance.
A further test showed that men's implicit self-esteem was negatively influenced when they thought about a partner's success, both when the success was relative and when it was not.
"In sum, men's implicit self-esteem is lower when a partner succeeds than when a partner fails, whereas women's implicit self-esteem is not," wrote the authors. "These gender differences have important implications for understanding social comparison in romantic relationships."