Women who date sexist men often become sexist themselves, new research suggests.
A study, led by social psychologist Matthew Hammond from the University of Illinois, examined more than 1000 couples in North America and New Zealand.
It involved couples aged 17-48 who had been together for an average of almost three years.
A man's attitude toward sexism was found to play a "distinct and unique role" in shaping his partner's views. It can take less than a year for the influence to show, the research found.
Women in the study were asked to categorise their own sexism and their other half's sexism.
There were two types used in the study: hostile and benevolent.
Hostile sexism is the belief that women are not equal to men. Benevolent sexism is the belief women are less competent and in need of protection.
It is typified by paternal behaviour, from encouraging smiles to holding doors open.
Researchers found that women who were with benevolently sexist men started to adopt their anti-feminist views - and support for those views increased over time.
Hammond said benevolent sexism appealed to some women because it reinforced their traditional outlook.
But the professor added: "These beliefs that seem romantic or chivalrous actually legitimise discrimination toward women who do not want to have a traditional relationship role."
The study also found that women who dated men who they did not perceive as being sexist began to value and endorse gender equality to a higher degree.
In previous research Hammond found when male partners exhibited benevolent sexism while helping female partners achieve a goal - in fitness, work, or school - the women felt less competent in their abilities.