
Literal research and reports on how that kind of language affects kids and their self worth later on in life. When girls hear that boys are being told they're not strong enough and in result makes them feminine, those girls often grow up to internalize the belief that they are less than. Believe me I trash talk my campers all the time in games, but I use language that doesn't demean a group of people...
Plus it's so simple to not do that. Today a camper told me that a fish walks faster than me (and it was deserved 😔). Idk I feel like I'm doing too much because my coworkers say I am, but my field of study has countless data (and just general lived experience) to show how harmful this everyday language can be.