nodding

interpretation

is generally built upon this rule: when a guy meets another guy, they nod up if they know each other and nod down if they don’t

usually when a guy meets another guy, they nod up if they know each other and nod down if they don’t

is done in this manner: downward nod for strangers, upward nod for friends.

Downward nod for strangers, upward nod for friends.

is different between the sexes --- women nod acknowledgment; men nod agreement.

Women nod acknowledgment; men nod agreement.