I always wave at oncoming cars when I’m running. I do this not because I’m a friendly guy, but I want to appear as a friendly guy. If it should happen (and it has) that I’m way out in the country and need a ride home, I want motorists to pick me up.

Waving has given me ample opportunity to study the return wave of drivers and passengers. Drivers typically have at least one hand on the steering wheel (hopefully), therefore the one-finger raise (index finger) is often used. Sometimes they will point the index finger.

Same goes for the two-finger raise, or point. Farmers in pick-up trucks will often include a head nod along with the finger wave, especially if they’re wearing a seed corn cap.