Also something I've pointed out before is that participation trophies aren't any different from achievements or experience points in video games. I doubt it makes the kid genuinely cocky or something, but it's a nice reward system to get them a dopamine hit and keep them at doing the task. The idea of team sports is you want to build life skills, and awards like participation trophies at a young age help encourage that. Whereas introducing a harsh competitive environment at a young age might discourage it for most kids. I'm sure if you do a study on behavioural problems, you probably won't find a large gap between generations, and within a generation the participation trophy kids might have fewer issues (in no small part due to the fact that team sports are sometimes a class indicator).