Well-meaning statements commonly expressed by parents and teachers can subtly perpetuate the stereotypes they are trying to debunk, a study has found.
On the surface, sentences like "girls are as good as boys at math" tries to convey that both sexes are equal in their abilities.
However, because of its grammatical structure, it implies that being good at math is more common or natural for boys than girls, the researchers said.
Researchers from Stanford University in the US tested the effects of the sentence, as well as variations like swapping "girls" with "boys," on a group of English-speaking adults.
They found that most people associate a natural math ability with the gender written in the second part of the sentence - what grammatically is known as the complement.
"Considering that several fields with large gender gaps like computer science and physics value raw talent, statements that imply that boys are naturally more talented could be contributing to women's under representation," said Eleanor Chestnut, lead author of the study published in the journal Cognitive Science.
"Adults, especially parents and teachers, should thus try to avoid consistently framing one gender as the standard for the other," she said.
The difference between "girls are as good as boys at math" and "girls and boys are equally good at math" may not be obvious, but each carries a slightly different meaning.
The first statement contains a so-called subject-complement structure, which compares girls to boys. "Boys" is the complement or a standard against which "girls," the subject, is examined.
The second sentence has a subject-subject structure and puts both girls and boys in the same position in the sentence, without comparing the two.
Researchers surveyed 650 English-speaking adults from the US to better understand how people perceive the subtle difference between such statements even if they do not realise it.
They divided study participants into five conditions, each with 128 people.
Participants read variations of a paragraph that summarised research that showed a lack of gender differences in math skills.
The text for each condition was almost identical except for a subtle difference in how the main finding was framed.
Participants read text with one of four statements: "girls do just as well as boys at math," "boys do just as well as girls at math," "girls and boys are equally good at math," and "boys and girls are equally good at math."
After reading the text, participants in all conditions were asked which gender they considered to be more naturally skilled at math.
Of those participants who read a text that included "girls are as good as boys at math," 71 per cent said boys have more natural math ability.
However, only 32 per cent of participants said the same after reading a text that contained "boys are as good as girls at math," researchers said.
When the researchers explicitly asked participants if they thought the sentence "girls are as good as boys at math" was biased in any way, people rated the statement as unbiased.
This shows that the power of such statements to imply inequality occurs without listeners realising it, researchers said.