A study published in Psychology of Men and Masculinity proposes that benevolent sexism and high social status may account for why men intervene when women are victims of sexual aggression. 

There are two dominant types of sexism: hostile and benevolent. While hostile sexism refers to a deep-seated dislike towards women who are viewed as subordinate, benevolent sexism refers to positive attitudes and chivalry towards women who are viewed as pure and worthy of protection.

Benevolent sexism is often more subtle, and highlights traditional gender roles, including women’s inferiority and the need to protect women. Previous research has found that men who believe that all men should attain high social status are more likely to intervene when women are victims of sexual aggression. 

This led the researchers to hypothesize that men will be more likely to intervene in situations of sexual aggression when (1) they are high in benevolent sexism or (2) they value social status as central to the male identity and are high in benevolent sexism.

The researchers believe that since benevolent sexism results in chivalrous attitudes towards women, it will cause men to believe their role is to protect women. In doing so, they will perceive themselves as a “white knight”, while simultaneously demonstrating their high social status. 

To test their hypothesis, the researchers recruited 148 men between the ages of 21 to 30 years old. Each participant was given a survey to assess their endorsement of traditionally masculine ideologies (e.g. “I think that a young man should try to become physically tough, even if he’s not big”).

Participants were also given a survey to assess their endorsement of hostile sexist beliefs (e.g. “women seek to gain power by getting control over men”) and benevolent sexist beliefs (e.g. “a good woman should be put on a pedestal by her man”). 

Next, the researchers measured each participant's bystander behavior using another survey (e.g. “I made sure a friend (or stranger) didn’t leave an intoxicated friend behind at a party”). 

The researchers found that, contrary to the first hypothesis, benevolent sexism wasn’t associated with bystander behavior. That is, men who scored higher on measures of benevolent sexism weren’t more likely to intervene when women were victims of sexual aggression. 

The researchers suggest this may be because interfering with another man's sexual encounter may lead to derogation from peers. 

However, in line with the second hypothesis, men who (a) valued high social status as central to the male identity and (b) were high in benevolent sexism were more likely to intervene in cases of sexual aggression. The effect was not replicated for men with low social status. 

The researchers further proposed that these men, who value being on top of a social hierarchy, may intervene in cases of sexual aggression because they view this behavior as consistent with the values of manhood (i.e. being a protector). 

Lastly, the researchers note that since benevolent sexism tends to reinforce stereotypes and gender inequality, it may only encourage men to help certain women (i.e. those who conform to gender role expectations).