I have to cross several streets on my (near) daily walk with the dog. Often cars just zoom by despite seeing us clearly standing at a crosswalk. Jerks!

But then there are the people that stop and let us cross safely. And for that I give a wave, and a “thank you.” It's for them seeing us, recognizing our need to cross safely, and giving a few seconds of their time to us so we can move along.

Some people do that thank-you wave every single time. Others stare straight ahead, pretending the car doesn’t even exist.

Psychologists say that tiny gesture isn’t random at all. On the surface, the “thank you” wave looks harmless and polite, like saying “good morning” in an elevator. Just a reflex. Yet when researchers observe these micro-behaviours in public spaces, they keep noticing the same thing. People who wave tend to share a cluster of personality traits that go far beyond basic good manners.

They’re more likely to be what psychologists call “high in agreeableness” and “high in perspective-taking”. In plain English: they spontaneously think about what the other person might feel. That tiny lift of the hand is a way of saying “I see you, I noticed you slowed down, and that matters.”

Psychologists call these things “prosocial micro-signals”. The wave, the nod, the brief eye contact — they’re low-effort, low-cost actions that still say, “We’re in this together.”

People who do them consistently often have what’s known as an internalized social norm: they don’t need rules or signs telling them to be considerate, they feel it as part of who they are. That doesn’t mean non-wavers are rude monsters. Some are just anxious, distracted, or lost in their thoughts.

Are you a waver, or one who strolls across like a boss looking straight forward?