Signaling is defined by Yvain as "a method of conveying information among not-necessarily-trustworthy parties by performing an action which is more likely or less costly if the information is true than if it is not true". Some signaling is performed exclusively to impress others (to improve your status), and in some cases isn't even worth that. In other cases, signaling is a side-effect of an otherwise useful activity.
For example, if doing something is easy for one type of person and hard for another type of person, you might do that thing just to get people to think you're the former type of person, even if the thing isn't in itself worth doing. This could explain many facets of human behavior, and reveal opportunities for reducing waste.
Not all signaling is about abilities. Signaling can also be about personality, current emotional state, beliefs, loyalty to a particular group, status within a group, etc.
Countersignaling is signaling that a naive observer might take to mean that one is the opposite of X, when in fact, one is X, used as a means to signal that one is, in fact, X. For example, aristocrats ("old money") may forgo gaudy bling in order to signal that they are not nouveau riche (new money), which may lead some people to incorrectly assume thatnot rich.
by Robin Hanson
by others