Researchers found that men who are stressed out become more self-centered and are less able to distinguish their own emotions and intentions from those of other people.
For women the exact opposite is true. Stressed women become more 'prosocial', according to the study carried out with the collaboration of Giorgia Silani, from the International School for Advanced Studies (SISSA) of Trieste, Italy.
"There's a subtle boundary between the ability to identify with others and take on their perspective - and therefore be empathic - and the inability to distinguish between self and other, thus acting egocentrically," said Silani.
"To be truly empathic and behave prosocially it's important to maintain the ability to distinguish between self and other, and stress appears to play an important role in this," Silani said.
Stress is a psycho-biological mechanism that may have a positive function: it enables the individual to recruit additional resources when faced with a particularly demanding situation.
The individual can cope with stress in one of two ways: by trying to reduce the internal load of "extra" resources being used, or, more simply, by seeking external support.
"Our starting hypothesis was that stressed individuals tend to become more egocentric. Taking a self-centred perspective in fact reduces the emotional/cognitive load," said Claus Lamm, from the University of Vienna and one of the authors of the paper.
"We therefore expected that in the experimental conditions people would be less empathic," Lamm said.
The starting hypothesis was indeed true, but only for males.
In the experiments, conditions of moderate stress were created in the laboratory (for example, the subjects had to perform public speaking or mental arithmetic tasks, etc).
The participants then had to imitate certain movements (motor condition), or recognise their own or other people's emotions (emotional condition), or make a judgement taking on another person's perspective (cognitive condition).
Half of the study sample were men, the other half were women.
"What we observed was that stress worsens the performance of men in all three types of tasks. The opposite is true for women," said Silani.
The study was published in the journal Psychoneuroendocrinology.