Temporary (or not) blood bond
Have you ever felt the eyes of a older man burning into the back of your skull when you get on the bus, and when you press the ‘stop’ button after he fails for the fifth time to successfully press it or picked up something that rolled out of his shopping bag, he thanks you, starts chatting, and even though the doors are open is in no rush to exit the bus? As if this simple altruistic gesture has created a blood bond.