Both the secular left and the religious right resist the notion that humans possess an innate "human nature". The idea disturbs long-held believes that the mind of an infant comes as a "blank slate" onto which experience and society make their mark.
Yet this view was undermined by the findings coming out of biological studies of the human mind, according to Prof Steven Pinker, professor of psychology at the Massachusetts Institute of Technology in Boston.
Prof Pinker discussed the evidence for human nature and arguments against the blank slate last night in Dublin during an Irish Times/Royal Dublin Society Science Today public lecture.
"We all have some idea of human nature and a concept of what makes people tick," he said. We use this understanding in our daily lives, when dealing with children and in education.
There were three typical populist views of human nature, he said. The blank slate idea argued that infants arrived with an untouched mind ready to be moulded by experience and the influence of society.
The idea of a "noble savage" was another view that held that humans started "good" but were inevitably corrupted by the failings of society. He described the third view as "the ghost in the machine", a force exerting influence in our lives. "This is something separate to our body that makes choices under free will."
None of these, however, has held up under the latest scientific findings of how our minds work. "All three have recently been challenged by biological science," he said. "These findings have been incendiary, both the political left and the political right in the US have been upset by them."
He expressed surprise at this however, saying that the evidence for innate human nature was readily available to any parent who noted differences between children and in the universality of human behaviour.
He identified four fears that could motivate resistance to the idea of innate human nature. One was the fear of inequality, typified by those who would argue that if we did not all start as a blank slate then we must start different, opening the way towards race or sex discrimination.
The second he describes as the fear of "imperfectability", the notion that we may be born with a dark side that cannot be corrected by experience or society.
The third is "determinism", that if our brains were hard-wired for human nature then our actions are not our own.
The fourth is "nihilism", he said. It is typified by the notion that our love for children or others is simply a chemical process without meaning.
"Even if evolution is a selfish amoral process, there is nothing to prevent a selfish amoral process from delivering a generous, moral being," he stated. "Just because our genes are selfish doesn't mean we are selfish."
The Blank Slate, The Modern Denial of Human Nature, by Steven Pinker is published by Penguin/Allen Lane and is available in bookshops for €35.
