

For men working together, stress plus coffee could be toxic

If a meeting becomes stressful, does it help, or make things worse, if team members drink lots of coffee? A study by Lindsay St. Claire and colleagues that set out to answer this question has uncovered an unexpected sex difference. For two men collaborating or negotiating under stressful circumstances, caffeine consumption was bad news, undermining their performance and confidence. By contrast, for pairs of women, drinking caffeine often had a beneficial effect on these same factors. The researchers can’t be sure, but they think the differential effect of caffeine on men and women may have to do with the fact that women tend to respond to stress in a collaborative, mutually protective style (known as ‘tend and befriend’) whereas men usually exhibit a fight or flight response.

The study involved 64 male and female participants (coffee drinkers at the University of Bristol with an average age of 22) completing various construction puzzles, negotiation and collaborative memory tasks in same-sex pairs. They did this after drinking decaffeinated coffee, which either had or hadn’t been spiked covertly with caffeine (the equivalent of about three cups’ worth of coffee). Stress was elevated for some of the pairs by telling them they would shortly have to give a public presentation, and by warning them that their participation fee would be performance dependent.

How large were the caffeine effects? The men’s memory performance under stressful conditions with caffeine was described by the researchers as ‘greatly impaired’ whereas caffeine didn’t affect women in the same situation. For the construction puzzles, caffeine under high stress conditions led men to take an average of twenty seconds longer (compared with no caffeine) whereas it led women to solve the puzzles 100 seconds faster.

A short-coming, acknowledged by the researchers, was that there were overall few effects of stress on the participants’ performance, no doubt in part because they’d been told they could bail out any time they liked (although none of them did). Further research is clearly need to replicate the findings and explore the possible underlying mechanisms. Such work is urgent, the researchers concluded, ‘because many … meetings, including those at which military and other decisions of great import are made, are likely to be male-dominated. Our research suggests that men’s effectiveness is particularly likely to be compromised. Because caffeine is the most widely consumed drug in the world, it follows that the global implications are potentially staggering.’



8 thoughts on “Coffee helps women cope with stressful meetings but has the opposite effect on men”

  1. Interesting stuff, could this highlight that the effects of caffeine on the sympathetic nervous system, coupled with men's sympathetic nervous system activation in response to stress leads to some kind of over stimulation?

    Furthermore, does this highlight that women don't exhibit a strong sympathetic nervous system response in response to stress, or merely that their sympathetic nervous system causes different effects?

    All useful and interesting stuff, nonetheless.

  2. I believe years of study have yet to show any negative and generally only mild positive effects of caffeine on cognitive performance. Presumably, any effect found here is due to the social aspect of the tasks (that do not seem all that standardised from what i read here – why not a simple n-back?) studied here. All in all, I'm rather sceptical of any effect, moreso one that can be described as large, found here. Was there any control (easily available as decaf)?
    I suppose I could do a meta-analysis on all my data, as I always ask how many cups of coffee people had before the experiment…

  3. Hi Mspape – the finding was based on a sex-caffeine-stress interaction, so it did seem as though the caffeine was having a differential effect on the sexes, specifically under stressful conditions. The control was decaf, which for some pairs was spiked with food-grade caffeine.

  4. Any control in the study to determine if people had back-to-back-to-back meetings prior to doing the puzzle exercises? 'Cause if you're trying to mimic male dominated settings where scary decisions occur (like the military), you should probably make sure you have the right context. Said another way, were these participants in danger of falling asleep prior to doing their puzzles?

    But I'd spend a bit more time flushing out the research agenda before I throw the “potentially staggering” implications around.

  5. I'm really skeptical of this.

    Caffiene, Amphetamines, and other stimulants have nearly always shown mild cognitive improvement and better retention.

  6. I'm glad someone blogged about this, but have to admit I didn't like the study. The authors explained the difference in that women have a tendency to befriend and cooperate when in high stress team situations whereas men don't.

    I think it could be argued that at least by socialization women are taught to be more cooperative in stressful situations and men more combative. However, drawing the link that coffee causes this in particular seems extremely doubtful to me. Possibly coffee increases stress, and men and women are taught to cope in different ways. I wish the studies authors had put a little more care into their conclusions.

  7. This study may be flawed by the overriding escape clause that they could bail on the study at any time. With that security, how can one be sure that stress is being properly applied to the experimental subject. The study might be reflecting how gender affects participation in a game

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