You're walking over to your calculus test when someone says 'Hey! You look nice today!'. According to a new study out of Israel, that compliment might lower your test scores… if only just a smidge.

Obviously this sounds a little crazy, and the study is just the first step in research looking into this phenomenon, but it's an interesting example of how subtle things might mess with us.

"I came across a post that a woman had published in a Facebook group named 'Women in Management'. She wrote about a job interview she had, where the interviewer (a man) complimented her about her eyes," explained study author Rotem Kahalon of Tel Aviv University to PsyPost.

"She asked how it was relevant, he said it wasn't, but she wrote that for her the interview was over after that question, her head was just somewhere else."

"This situation got me thinking about how subtle things have an impact on us, and I started wondering what kind of effects they have, and, if they are experienced the same way by both men and women," she added.

In one experiment, the researchers took 88 female Israeli university students, and when the women wrote about past situations in which they had received compliments, they actually scored slightly lower scores in a difficult maths test than those that didn't write anything.

In the second experiment, the team took 73 female and 75 male university students and made them take the same hard maths test after receiving - or not receiving - a compliment from a researcher of the opposite sex.

Although some of the students felt happier after the compliment, the test scores fell slightly - and this happened for both men and women.

So what does this actually mean?

Well, right now we'll have to take the results with a grain of salt. The number of people in the study is relatively small, and the results of the maths tests were only slightly lower for those that received the compliments.

Out of the 19 questions, for example, the average maths score for those receiving the compliments was 11.3, and those without 12.2 – not exactly a massive difference.

Plus, the researchers can't actually tell us why this is happening, the study just looked at if it was happening, so we'll have to wonder about compliments and maths for a bit longer.

But if these weird results are replicated in further studies, it does make an interesting point about how even something as benign as a compliment can affect the way we think.

"We believe it is important to raise the awareness of the public - teachers, professors, bosses and coworkers, and so forth - to the negative effects this kind of seemingly positive situation might have," said Kahalon.

"In our research both men's and women's cognitive performance was negatively affected by the appearance compliment, but as outside of the lab women are those who usually receive appearance comments, they are probably those who are mostly affected by it."

The research was published in Psychology of Women Quarterly.