As if things weren't bad enough for men who – not to put to fine a point on it – were at the back of the queue when the good looks were handed out, it seems they can expect more than their fair share of rough treatment from their partners.

By one of nature's cruel ironies, facially challenged chaps are most likely to get a hard time from their wives at the time of the month when she is most fertile, according to a scientific study in the US. As if this weren't bad enough, women whose husbands are less sexy also tend to be more attracted to other men at that time.

Researchers at the University of California found women whose partners were low in sexual desirability become more distant, more critical, and less tolerant during high-fertility. This goes back to when the needs of women to get good mates, and therefore healthy children, were paramount.

The researchers carried out various tests and quizzed women mated with less sexually attractive men at different times of the monthly cycle. They found that, as they moved from least fertile to most fertile, the women's rating of closeness in their relationships dropped by around 15 per cent. Women whose partners were the most sexually attractive experienced the opposite effect.

One theory for this is based on the idea that women make a compromise when they choose a partner, between men who are steady and men who are sexy. One possibility is that those who opted for Mr Steady feel more negative about their choice when they are at their most fertile.

The good news for unattractive men is that this doesn't seem to diminish the longevity of a relationship: "The negative feelings appear fleeting, and they don't seem to affect a woman's long-term commitment to her romantic relationship. Even when these women are feeling less positive about their relationship, they don't want to end it."

The bad news is that the process of discrimination against ugly chaps begins long before they settle down. A separate study of women asked to interview more, and less, good-looking men found that they chose to wear much more appealing clothing for the good-looking chaps.

In this study, involving 150 women aged 17 to 48, and published in The Journal of Experimental Social Psychology, researchers told each of the women that they were going to interview a man, and were given sight of a questionnaire that he had completed. They were also told that it was policy to wear a shirt for the interview and they had a choice between red and green.