Turning in the wallet you found is a tiny test with a huge answer about who you are.

Moments with no audience are where character is actually decided, because there is no reputation to manage and nothing to gain. Handing it in is a small act with a clear answer attached to it, and the answer is one you will carry rather than announce. Whoever lost it also gets their day back.

When something like this lands in your hands, act before the internal negotiation starts. Hand it in and do not wait for thanks. The information you get about yourself is worth more than the contents.