NEW YORK, (Reuters Life!) – Just a pat on the back  or a reassuring touch on the arm can be a powerful tool to  influence behavior, according to new research.

And it could determine whether someone invests in a risky  financial venture or decides to play it safe.

“It’s a very effective way of suddenly influencing people’s  behavior without them realizing they are being influenced,”  said Jonathan Levav, a professor of business and marketing at  Columbia University in New York.

“If you’re a doctor, or are in sales, this is a form of  communication you might want to keep in mind,” he added in an  interview. Levav ‘s findings, which are reported in the journal  Psychological Science, are based on a series of experiments  involving touch.

In one study 67 men and women were asked to choose between  a cash payoff and a risky gamble and then touched on the  shoulder and back by male and female researchers.

Levav and his co-author Jennifer Argo, of the University of  Alberta in Canada, found was that both sexes were more likely  to select gambles with no guarantees of a payoff if they had  been made to feel more comfortable, especially if touched by a  woman.

In another experiment, 105 people were asked to allocate  their money between two investments — a bond that delivered a  four percent yearly return or a risky deal with no guaranteed  return.

Again, people who were lightly touched on the shoulder by a  woman were more likely to select the option with the most  risk.

Levav and Argo suggested that the connection between  comfort and risk goes back to our earliest recollections of  human bonding. “A simple pat on the back of the shoulder by a female in a  way that connotes support may evoke feelings that are similar  to the sense of security afforded by a mother’s comforting  touch in infancy,” they wrote in the study.