(PhysOrg.com) -- The Japanese have impressed the world with the relative calm and order they have maintained in the aftermath of one of the world’s worst natural disasters.

Joan Chiao, a Northwestern University neuroscientist who works in one of the few labs dedicated to cultural and social neuroscience, offers perspective on how ’s collectivist culture may offset some of the worst mental health risks that follow such catastrophes.

One of the most profound ways that people across cultural groups differ markedly, cultural psychology demonstrates, is in how they think of themselves. “People in collectivistic cultures, relative to those in individualistic cultures, are more likely to endorse behaviors that increase group cohesion and interdependence,”said Chiao, assistant professor of psychology in the Weinberg College of Arts and Sciences.

Consistent with a collectivistic ethos or way of being, the Japanese are responding relatively calmly to the tragedy and helping each other in a way that puts a higher premium on the group rather than on the individual, she said.

This collectivistic response is likely to minimize the mental health costs of being hit by a colossal earthquake, followed by a tsunami and nuclear threats. “By working together in smaller groups within their in-group, it’s likely that the Japanese -- particularly the population genetically susceptible to anxiety and depression -- may actually minimize mental health risks,” Chiao said.

Cultural differences are overriding evolutionarily hard-wired responses. “In the face of natural disaster, humans are evolutionarily hardwired to express strong emotions as a means of getting help and responding to others who need help,” Chiao said. Such emotions play an important role in eliciting empathy and calling people to action.

“But in this case,” Chiao said, “the Japanese people’s minimal expression of emotion, as they look for orderly ways to help themselves and others, is beneficial, for example, to rescue workers who need to be focused on critical tasks.”

But there can be a downside to such collectivistic behavior, she suggested, pointing to “the reports of survivors who were not proactive in their own distress calls, as they focused on orderly ways to help themselves.”

Chiao pointed to stories about Japanese people putting the welfare of others before their own needs and of how they are stoically coping with the tragic deaths of loved ones, the loss of friends and family members as well as personal property and uncertainty about their jobs and futures.

One news report focused on a tiny fishing hamlet in Japan that washed away nearby bridges, phone lines and cellphone services, leaving survivors shivering and cut off at a hilltop community center. Almost as soon as the waters receded, the survivors began dividing tasks and within days re-established a complex community, with a hierarchy and division of labor, even creating a committee that served as an impromptu governing body.

“Normal Japanese life is about cooperating with your in-group members to solve basic problems,” Chiao say. “And the response we are seeing in Japan today to the massive destruction of life as usual is bringing back some normalcy to their culture.”

More than 30 years of cultural/psychological research, she said, has shown that the simple dimension of individualism versus collectivism makes a big difference in how people feel, think and motivate themselves to accomplish goals or tasks.

Chiao is the author of “Culture-gene coevolution of individualism-collectivism and the serotonin transporter gene” (Proceedings of the Royal Society B: Biological Sciences).

The study shows that a genetic tendency to depression is much less likely to be realized in a culture centered on collectivistic rather than individualistic values. Remarkably, according to the study, in collectivistic nations, such as those in East Asia -- where nearly 80 percent of the population is genetically susceptible to depression -- depression is significantly lower than in individualistic nations, such as the United States and Western Europe.

In other words, a genetic vulnerability to depression is much more likely to be realized in a Western culture than an East Asian culture that is more about we than me-me-me.

The research strongly suggests that medical doctors need to work with basic scientists to better understand the complex dance that biology and culture play in both mitigating and causing mood disorders such as depression.