London, Sept 10 : Superstitions like crossing black cats, walking under ladders or stepping on cracks in the pavement have actually evolved to help people survive with "better safe than sorry" approach to life, says a leading researcher.
According to Kevin Foster, an evolutionary biologist at Harvard University, a prehistoric human might associate rustling grass with the approach of a predator and hide. Most of the time, the wind will have caused the sound, but "if a group of lions is coming there's a huge benefit to not being around."
He said that the tendency to falsely link cause to effect sometimes works in a positive way.
The research team including Foster and Hanna Kokko, of the University of Helsinki, Finland developed a mathematical model in which they gathered the situations where people are likely to adapt superstitious beliefs.
The real and false associations often take place when various potential "causes" signify an event.
Michael Shermer, publisher of Skeptic magazine, has also given in a similar explanation for superstitious beliefs.
"Our brains are pattern-recognition machines, connecting the dots and creating meaning out of the patterns that we think we see in nature," New Scientist quoted Shermer, as saying.
"Sometimes A really is connected to B, and sometimes it is not. When it isn't, we err in thinking that it is, but for the most part this process isn't likely to remove us from the gene pool, and thus magical thinking will always be a part of the human condition," he added.
However, not all superstitions carry on because of their evolutionary kick.
"Once you get to things like avoiding ladders and cats crossing the road, it's clear that culture and modern life have had an influence on many of these things," said Foster.
"My guess would be that in modern life, the general tendency to believe in things where we don't have scientific evidence is less beneficial than it used to be," he added.
Foster said that rustling leaves and say, a full moon, indicating the arrival of the group of loins, might tilt towards superstition more than a single "cause" would.
However, Wolfgang Forstmeier, an evolutionary biologist at the Max Planck Institute of Ornithology in Starnberg, Germany, said that by linking cause and effect - often falsely - science is a simply dogmatic form of superstition.
"You have to find the trade off between being superstitious and being ignorant," he said.
"By ignoring building evidence that contradicts their long-held ideas, "quite a lot of scientists tend to be ignorant quite often," he added.