A common example of where rationality and truth-seeking come into conflict is the case where organisms display their beliefs - and have difficulty misrepresenting them. In such cases, it may thus benefit them to believe falsehoods for reasons associated with signalling their beliefs to others:

"Definitely on all fronts is has become imperative not to bristle with hostility every time you encounter a stranger. Instead observe him, find out what he might be. Behave to him with politeness, pretending that you like him more than you do - at least while you find out how he might be of use to you. Wash before you go to talk to him so as to conceal your tribal odour and take great care not to let on that you notice his own, foul as it may be. Talk about human brotherhood. In the end don't even just pretend that you like him (he begins to see through that); instead, really like him. It pays."

• Discriminating Nepotism - as reprinted in: Narrow Roads of Gene Land, Volume 2 Evolution of Sex, p.359.