Sure you could. 23 year olds who like to attend pokemon meetups. University chess club members. Small town attendees of quilting bees. Maker faire regulars.

They're self-associations largely based on personal interests, so it shouldn't be surprising that there are common personality traits within the groups. You miss out if you blanket-judge people based on them, of course, but that doesn't make them invalid.

That's in contrast to race, gender, etc. where the group is not self-selecting.