Chivalrous behaviour from young boys may be an indicator they'll grow up to be sexist men, psychologists at Victoria University have found.
The international study, carried out in partnership with New York University (NYU), found that both boys and girls have ingrained sexist attitudes towards women.
Girls change these attitudes as they age, however, boys tend to keep their "benevolent, patronising views", surmises the study published in the scientific journal Sex Roles.
The research was conducted through interviews with 200 children aged five to 11 in New York City and Urbana-Champaign, Illinois, in which kids were asked whether gender-based statements were right or wrong.
These include benevolent statements, such as 'men need to protect women from danger' and hostile ones, like 'women get more upset than men about small things'.
The research finds that while children's hostile sexism decreased with age for both boys and girls, benevolent sexism decreased with age only for girls.
NYU Associate Professor Andrei Cimpian says boys may be less likely to recognise benevolent attitudes as "patronising".
"They may hold on to the belief that men ought to protect women because this view is in line with social norms and may be reinforced throughout their upbringing," Cimpian said.
Victoria University's Dr Matthew Hammond said the data shows that some principles taught to young children are gendered and could be harmful down the track.
"This suggests we need to be cautious about seemingly protective beliefs that are gendered such as 'boys should never hit girls' because such beliefs may go hand-in-hand with views that girls are weaker or overly emotional," Hammond explained
"The egalitarian form of belief is that 'people should never hit anyone'."
Prof Cimpian says while it may seem cute "when a boy acts in chivalrous ways toward girls, or when a girl pretends to be a princess waiting for a prince to rescue her", it could be a worrying sign.
"Many times, this is just play with no deeper meaning," he said.
"But other times, these behaviours - even though they may seem inoffensive - might signal that children view women in a negative light, as weak, incompetent, and unable to survive or thrive without a man's help."
Dr Hammond is now launching a follow-up study into when and why some people start believing in sexist ideas, and when and why others reject them in favour of more egalitarian attitudes.