Rather than succumbing to the primitive “fight or flight” instinct, men actually become more sociable and cooperative when under stress, according to new psychological study.

Researchers from the University of Freiburg, Germany said that their latest findings debunk “a nearly 100-year-old doctrine,” that while women showed an alternate "tend-and-befriend" response to stress and became more protective and more sociable, and men became more aggressive.

"Apparently men also show social approach behavior as a direct consequence of stress," co-researcher Bernadette von Dawans of the University of Freiburg in Germany said in a statement.

The study, published in the journal Psychological Science, consisted of 67 male students from the University of Zurich. Researchers tested the participants’ response to stress by having half of the male students perform public speaking tasks and complete a tough mental math test. The other half of the participants just mimicked these activities in a more relaxed way.

After the participants were primed in their respective groups, they were asked to play a series of trust and sharing games with real money at stake with another group of volunteers. Researchers explained that the games were designed to measure how much a person is willing to trust their partners, whether participants will try to earn their partners trust or betray them and if participants will share or hoard money.

The participants also played a simple roll-the-dice gambling game to show how aggressively risky they were willing to be in a non-social context.

Researchers monitored participants’ heart rate and concentration of the stress hormone cortisol in their saliva during the whole experiment.

Researchers found that despite the traditional view that when under stress, men become more aggressive, stress actually increased friendly and pro social behaviors in men. In fact, the higher their heart rates and cortisol levels, the more trusting, reliable and generous behavior they became when playing the games.

Psychologists noted that there was no difference in anti-social or risk-taking behavior between the stressed and the control group. For instance, stressed-out participants were any more likely to take big risks than non-stressed participants, which means that stress response may be specific to social behavior.

"From previous studies in our laboratory, we already knew that positive social contact with a trusted individual before a stressful situation reduces the stress response,” Professor Markus Heinrichs said in a statement released by the journal.

“Apparently, this coping strategy is anchored so strongly that people can also change their stress responses during or immediately after the stress through positive social behavior," he added.