Costly Signaling vs. Cheap Talk

Mark Jeffreys

Associate Professor of Behavioral Science, Utah Valley State College

jeffrema@uvsc.edu

The transition from proto-language to modern language began when part 
of human communication became detached from costly signaling and 
evolved into a separate channel of  "cheap talk." Language is not 
necessary to signal one's intentions or resource-holding potential (RHP). 
Those social utilities precede modern languages. Whereas all forms of 
honest signaling, including both emotional and behavioral cues, are easy 
to learn (or involuntary) but costly to perform, human languages, dialects, 
and even "lingos" are costly to learn but easy to perform. Moreover, 
humans produce false statements as easily as true statements, and while 
we are adept at recognizing a conspecific's predisposition to cooperate or 
defect from nonverbal cues, we are inept at identifying factual verbal 
deceptions. Language is not under selection pressure to honestly signal 
affect or intention, nor do humans trust language alone in those domains.

This paper reports results from a series of double-blind, anonymous 
economic experiments utilizing "sudden-death" elimination tourneys of 
prisoner's dilemma games in which players can opt to "protect" or 
"abandon" fellow players. Elimination in each round is probabilistic rather 
than determinate. In the control treatment, players have no communication 
and are randomly matched in each round. In variable treatments, players 
are able to advertise for partners who will protect them, either by signaling 
with 1-word markers or 3-word phrases or sentences, or by offering a 
share of their stake to any potential partner. Results showed that 1-word or 
3-word phrases ("cheap talk") had no significant effect on cooperation or 
survival, whereas concrete shares ("costly signaling") led to enhanced 
cooperation and greater success of both the proposers and acceptors.