[jnxx]

Trust is also essential for any form of symbolic information exchange.

Humans communicate using symbols. That could be patterns of sound waves, gestures, or written characters.

If we can't trust that the communicated symbols match their agreed meaning, what is the use of them? Communication breaks down quickly, and being social individuals which inter-depend on others, we can't live without communication. Nobody likes a liar, and the reason is, the words they give us do not match what they mean. (Perhaps not only humans. I read that dolphins readily come and rescue individuals which are drowning - including humans - but they punish individuals which fake drowning.)

And that goes from every stratum of social interaction, from big treaties to selling a bagel. Would you sell a bagel for a fake dollar bill? The number on it is a symbol as well, it has a meaning.

So it is right down one of the very bases of human cooperation.