I'm looking for advice on character development

I'm currently working on a team based story with a lot of characters and am looking for ways to really make their personalities stand out from one another. When I'm writing out their character profiles I get to a certain point where, two male characters, for example, seem like the same character wearing another face. I give them different traits, and backgrounds but when I think about how they'll react to things, they seem like copies of one another. I thought perhaps I wasn't developing their personalities enough, but maybe it's another issue? Any advice will be greatly appreciated and I hope this edit clarifies things a bit.