Gender-tailored marketing messages are fairly common, but research shows they can have the opposite effect and repel consumers, especially women. In fact, they often backfire to the point of dissuading women from choosing a product they would have considered if the company hadn't talked about their gender so much, a study by Harvard Business School found.

The reason for this lies in human nature. People tend to resist being categorized (or made to feel like they are unwillingly reduced to a single identity) particularly when the product they're being nudged toward evokes a stereotype about their gender.

Suggesting that women will go crazy over a product wrapped in pink packaging just because some marketer assumes that all women love pink can come across as downright insulting, co-researcher Leslie K. John, the Marvin Bower Associate Professor at HBS, said.

"In a way, this project reminds me of my childhood," John explained. "When I was a kid, I had a babysitter who said, 'Leslie, your favorite color is pink.' She would put pink bows in my hair. Everything had to be pink. This project is partly a reaction against this feeling that just because I'm a girl doesn't mean I love pink! There's something very off-putting about feeling like you're being reduced to a single category of membership."

But where does this false notion come from? Why do companies keep trying to sell their products by emphasizing the buyer's gender? Well, the answer to this question might lie in one 2017 Pew Research Center survey.

It discovered that Americans think men and women are basically different in the way they express their feelings, their physical abilities, their personal interests, and their approach to parenting. But there is no public consensus on the origins of these differences.

I think marketers know this. Maybe some of them just haven't realized that to have an opinion and to base your purchasing decision on it are two different things.

This applies to other aspects, not only gender. According to previous research, for example, even stereotypes that cast people in a positive light—such as Asians excel in math—can trigger a negative reaction from these groups.