Robert Trivers in New Statesman:
Deception is a very deep feature of life. Viruses practise it, as do bacteria, plants, insects and a wide range of other animals. It is everywhere. Even within our genomes, deception flourishes as selfish genetic elements use deceptive molecular techniques to over-reproduce at the expense of other genes. Deception infects all the fundamental relationships in life: parasite and host, predator and prey, plant and animal, male and female, neighbour and neighbour, parent and offspring.
Viruses and bacteria often actively deceive to gain entry into their hosts: for instance, by mimicking body parts so as not to be recognised as foreign. Or, as in HIV, by changing coat proteins so often as to make mounting an enduring defence almost impossible. Predators gain from being invisible to their prey or resembling items attractive to them – a fish that dangles a part of itself like a worm to attract other fish, which it eats – while prey gain from being invisible to their predators or mimicking items noxious to the predator.
Deception within species is expected in almost all relationships, and deception possesses special powers. It always takes the lead in life, while detection of deception plays catch-up. As has been said regarding rumours, the lie is halfway around the world before the truth puts its boots on.
But here I want to talk about self-deception.