Must we become what we're near?

I’ve seen a number of thoughts similar to this from Shane Parrish:

We unconsciously become what we’re near. If you work for a jerk, sooner or later, you’ll become one yourself. If your colleagues are selfish, sooner or later, you become selfish. If you hang around someone who’s unkind, you’ll slowly become unkind. Little by little, you adopt the thoughts and feelings, the attitudes and standards of the people around you.

Shane Parrish, Farnham Street

I wonder if anyone’s considered whether the opposite could happen. Let’s assume that I’m, say, a kind person working with someone who’s unkind. Maybe, just maybe, the person I’m near will become more kind rather than the other way around. Must things always trend toward the negative? I’d like to think not.