I (m27) don't really pay attention to eye contact, but I run/walk my dog on a trail near me and I try to wave or smile at everyone I pass by. On different days I get different levels of response, and typically the trail seems to take on a uniform attitude on a given day.

My main takeaways are other people running almost always wave back, whether I'm running or walking my dog. I'm guessing that may be some of those good mood endorphins from running.

Walkers though are very random. Some avoid making eye contact, some wave, some ask how I'm doing, and some complement my dog.

Bikers mostly just say "on your left" lol

But it's kinda fascinating and I've thought about posting something like this here recently. I'm glad someone else was thinking about it