You know it. You don’t need scientific evidence to back it up.
When you treat someone else with kindness, you feel good. When someone is kind to you, you feel good. When you witness someone else being kind, it makes you feel good.
You know it. You don’t need the evidence, but scientists don’t believe anything without cold, hard numbers. So they’re finding them. Telling us something we’ve known all along. Here are two videos about their findings.