Coffee helps women stay focused but throws men off-track mentally, according to a recent British study.  An experiment designed to examine the effects of this popular beverage in the workplace displayed a significant difference as to how male and female subjects coped with stress after putting caffeine in their body.

For this study, published in the Journal of Applied Social Psychology, 64 volunteers were divided into same-sex pairs. The teams were challenged to solve puzzles, complete memory tests, and put together an oral presentation.

Each person was given a cup of coffee beforehand; half of them were decaffeinated, without the test subject knowing. The researchers observed that men who drank the caffeine found it difficult to think clearly while performing the tasks at hand, and took 20 seconds longer on average to finish the puzzles than the men with decaffeinated coffee.

Female subjects found their focus boosted in comparison to the women who did not have caffeine in their drink, and beat them at the puzzles by a margin of 100 seconds.

The impact was clear in not only test scores, but behaviour. Men tended to behave more aggressively and erratically after having coffee, however, the women who drank coffee were especially alert and cooperative. This suggests that the female body ihas more immunity to the reinforcing effects of caffeine while still enjoying its benefits.

One might wonder whether other factors, such as the amount each test subject consumed, could skew the results. “Amounts were equal per kilo of body weight,” said psychologist Lindsay St. Claire of the University of Bristol, who led the study. “We wanted to test an amount of caffeine equivalent of having an extra cup or two, as one might at a meeting, where free drinks are provided.”

St. Claire said she is very interested in examining the implications of a seemingly innocuous coffee habit on professional performance and social dynamics.

"The side effects of caffeine are subtle, but have the potential to snowball very quickly," she said. "Because caffeine is the most widely consumed drug in the world, the global implications are potentially staggering," said St. Claire,

The purpose of the experiment was to create a realistic situation as to pinpoint how the average person’s coffee might actually increase stress instead of reducing it, in ways that often go unnoticed.

“Our research wasn't set up to examine sex differences,” says St. Claire, “so that aspect of the research was exploratory.”