We belong to a remarkably quirky species. Despite our best efforts, some of our strangest foibles still defy explanation. But as science probes deeper into these eccentricities, it is becoming clear that behaviours and attributes that seem frivolous at first glance often go to the heart of what it means to be human.
Most of us have our own superstitions, even though we know rationally that they cannot work. Yet superstition is not entirely nonsensical.
Our brains are designed to detect structure and order in our environment, says Bruce Hood at the University of Bristol, UK. We are also causal determinists - we assume that outcomes are caused by preceding events. This combination of sensing patterns and inferring causes leaves us wide open to superstitious beliefs. "But there are very good reasons why we have evolved these capabilities," Hood adds. Spotting and responding to some uncertain cause-and-effect relationships can be crucial for survival.
Our ancestors would not have lasted long if they had assumed that a rustle in the grass was caused by wind when there was even a small chance it was a lion. And it is worth making false-positive mistakes to get these relationships right. Kevin Foster of Harvard University and Hanna Kokko from the University of Helsinki, Finland, used mathematical modelling to show that whenever the cost of believing a superstition is less than the cost of missing a real life-or-death association, superstitious beliefs will be favoured by evolution (Proceedings of the Royal Society B, vol 276, p 31).
Religion offers another possible evolutionary benefit of superstition. "[Religious faith] involves a susceptibility to believe in a spirit world and its efficacy - even if it doesn't actually work," says Dunbar, who is a leading proponent of the idea that religion is adaptive. He thinks religion's main function is to persuade a community to toe the line, so promoting cohesion. This is achieved in part by tapping into our natural propensity to believe in supernatural beings that can influence our fate.
Although it is in our nature to be superstitious, cultural and environmental factors clearly influence how superstitious an individual actually is. For example, when we feel we are losing control over our lives, we tend to become more superstitious. One study found that people living in high-risk areas of the Middle East, such as Tel Aviv, are much more likely to carry a lucky charm than other people. Another showed that the growth rate of evangelical churches in the US jumps 50 per cent with the downturn of each economic cycle. Nobody is immune. "We can all shift ur supernatural inclination depending on the circumstances," says Hood. "There are few atheists in a plane that is plummeting from 30,000 feet." More at:Ten mysteries of you
