Though politicians are regarded as scum, government as a machine is held to be almost infallible. - Matt Ridley

Stress can alter the expression of genes, which can affect the response to stress and so on. Human behavior is therefore unpredictable in the short term, but broadly predictable in the long term.

Simple determinism, whether of the genetic or environmental kind, is a depressing prospect for those with a fondness for free will.

Humanity shares this profile of ardent, polygamist males and coy, faithful females with about 99 percent of all animal species, including our closest relatives, the apes.