Geoffrey Miller in The Mating Mind:

Signals don’t usually convey information about the world, because signallers have so many reasons to lie about the world.

Miller notes that there is competition to make interesting points in conversation as part of a competition for status. I was trying to think through, though, what are the advantages to the listener rather than the speaker? Given the potential to be deceived by another’s speech, why do we listen?

One of the criteria we generally use for interestingness is truthfulness. Saying something interesting but untrue seems to be regarded as cheating in the interesting conversation game, and can be used to effectively disqualify a player. Just as making showy donations to charity demonstrates a person’s wealth, one can imagine that genuinely useful and true communication (because it takes greater effort to know useful things) is also a marker of fitness. So it’s still advantageous for those lower down the status hierarchy to listen to those who are showing off their knowledge, but the status goes to those who can provide the advantageous knowledge.