Another piece of the puzzle fell into place when Rule performed fMRI scans on his subjects. He expected to learn that the Americans were using more analytical areas of the brain and the Japanese more emotional areas. But what he discovered surprised him: both groups were using the same part of the brain – the amygdala. Sometimes called the “lizard brain”, the amygdala, which has been with us since the early days of our evolutionary journey, helps us detect threats, but it has a more general function as well, signifying increased attention to any object in the outside world. In this case, the amygdala was firing for both the American and the Japanese groups when they saw the picture of the leader they preferred.
“It was a little bit of a surprise,” Rule admits. The finding “essentially says that even though we are leading to different outcomes, we are getting there through the same means”. But what accounts for the strong differences in preferences, leading to very different actions in the real world?
Part of the answer might lie in a similar set of studies done by Freeman. He measured the brainwaves of American and Japanese subjects who were shown silhouettes of bodies in postures categorised as “dominant” and “subordinate” (for example, one of someone standing tall with arms crossed and another of someone with head bowed and arms hanging). “It’s been known for a long time that Western cultures encourage dominance and Japanese cultures more subordination in line with collectivist thinking,” Freeman says. “I was looking to see if these East Asians and Westerners perceive dominant and subservient bodies in a different way.”
The results, published in the journal Neuroimage in April 2009, indicate that here, too, people often travel the same route yet end up at destinations miles apart. The silhouettes matching cultural preferences activated another distinct area of the brain in both groups: the limbic reward system. This is the system that releases dopamine into the bloodstream in response to pleasurable stimuli such as drugs, sex, or food. But it’s also engaged whenever the brain wants to tell the body to go after something in the outside world – to pick up a desired cup of coffee or grab a favourite magazine off the rack.
“I found that dominant bodies activated this classic kind of reward circuitry in Westerners and subordinate bodies activated the same reward circuitry for Japanese people,” says Freeman. What’s more, the magnitude of the limbic response corresponded nearly exactly to the subjects’ responses to questionnaire statements about their level of dominance in the world (“I want to control the conversation” and “I am not afraid of providing criticism”). “So if I’m an American, the more dominant I behave in the real world, the more my brain activates the reward regions when thinking about dominance,” Freeman says.
While it’s impossible to rule out genetic differences between races to explain these differences in brain function, evidence increasingly points to culture as the deciding factor. Ambady and Bharucha both caution that further studies are needed – perhaps involving adopted children or immigrants – to determine exactly where genetics ends and culture begins. The most recent studies in the field, however, have already begun to show how malleable the structure of the brain is in response to cultural stimuli.
Joan Chiao, professor of psychology at Northwestern University who coined the term cultural neuroscience, conducted a study in October 2009 that showed distinctively how culture can override genetic imperatives. The study looked at both genetic and cultural factors influencing depression. It found that East Asians disproportionately possess a genetic trait that makes them more susceptible than Americans to depression when exposed to stress. And yet Americans have a higher incidence of depression. Chiao concludes that the collectivist culture of East Asians supersedes their genetics in helping to fight off depressive tendencies.
Despite their promise, however, the implications of cultural neuroscience are also rife for misinterpretation. Freeman worries it could be misconstrued to promote negative stereotypes. “I don’t want people to jump to conclusions that every American is wired to love dominance and every Japanese person is wired to love subordination,” says Freeman. “For Western readers, through the lens of their own culture, there is a lot of value judgment in that.”
Ambady also counsels caution. “The field of cultural neuroscience is very young,” she says, “and we tend to imbue these activations with lots of meaning.” The mainstream media often take the wrong message from cultural neuroscience research, reporting that if differences are found on the level of the brain, they must be somehow hard-wired. But evidence to the contrary abounds. Take the case of Korean Air, where flight crews succeeded in unlearning aspects of their culture that compromised their performance. “What cultural neuroscience shows,” Ambady says, is that the brain is “not fixed – it’s malleable.”
At the same time, the young field can also help us understand differences that do exist between cultures – and potentially lead to greater cooperation on international trade, security, and environmental protection. For that to occur, however, we need to overcome big neurological hurdles. With exposure to other cultures, perhaps, the brain can absorb different ways of perceiving and responding to the world. At the very least, being aware of how deep-seated our perceptions are can help us recognise – maybe even overcome – our natural prejudices.
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