When a smile is a bad sign...

REPORTS FROM THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

We must look not only internally but also at a cultural level to try to define a universal human nature. Steve Farrar reports

The Samoan chief smiled. Brad Shore, a 20-year-old Peace Corps volunteer teacher, had not been certain how well received his decision to decline the headman's invitation to lodge with his family while a new home was built for him would be. But the smile reassured him that there was no problem - he had caused no offence.

Six months later, sitting in the leaking, windowless house that the unfailingly polite chief still insisted would be finished soon, he reflected on how an expression of an emotion as simple as a smile can carry very different meanings in different parts of the world. For example, he had come to learn that in Samoa, a smile can also convey intense irritation.

Shore, who is now a professor of anthropology at Emory University in the United States, recounts his Samoan experience as an illustration of the complexity of humanity and how any search for an intrinsic "human nature" can run into trouble if it focuses on a hunt for such unifying themes. Smiling and the recognition of smiling as an expression of happiness and approval have been identified by psychologists as fundamental elements of the human psyche, part of a basic social tool-kit that humans worldwide share.

Shore is not so sure it as easy as that. "Some would say it is part of human nature to have these basic emotional responses. But the rules that govern when an emotion can be displayed are highly variable," he told the BA. "Even the most basic and shared human impulses, such as a smile, can become culturally modified. That chief always smiled at me, but my house was never finished."

Traditional attempts to define human nature, both theological and scientific, have focused on exploring what unites us as a species, in the belief that all humans have essentially the same potential. It is in the variability of the outcome of the interaction between biology and culture - what made the Samoan smile so deceptive to a westerner - that Shore believes we come closest to reaching a concept of human nature.

This is a debate that has raged for centuries and, given the vagueness of the term itself, is in little danger of reaching any real resolution. Different disciplines throw up different ideas, and even within a single community there can be very fundamental disagreements.

Like Shore, Harvey Whitehouse of Queen's University Belfast is an anthropologist. But for him, it is a pointless exercise to try to separate biology and culture and meaningless to talk of interaction.

The development of the human mind depends as much on patterns of social behaviour as it does on the initial physiology of the brain itself, he claims. For example, the host of weird and wonderful expressions pulled by a newborn baby are limited by the physical make-up of its face. However, those that trigger an appropriate response from those people around the infant will shape the way those expressions are used in later life.

"We have to see human nature as a complex combination of things that are not only 'inside' us but also around us at a population level," Whitehouse said.

As a linguist, Jim Hurford of the language evolution and computation research unit at Edinburgh University finds this subtlety hard to appreciate. If culture and biology are two sides of the same coin, they are easy to distinguish between, he reasons.

Language is the oldest, most complex tradition of any community, a common, defining thread of humanity and one of the keys to our success as a species. If we have any hope of getting a grasp on any unifying theme of humanity, it surely must be reflected here. The ability to grasp language is universal, a biological predisposition to complex grammar. The specific language with its particular grammar is cultural, though there appear to be common patterns throughout the world.

Like Shore, Hurford believes human nature may be found in the interaction between the two. But he thinks there is no need to interpret the Samoan smile as anything more than a confirmation of this.

"In speech, you very often say the exact opposite of what the words mean - you add another layer of meaning to known words," he said. "The basic meaning of a smile is universal. But another layer of meaning has been added in the Samoan culture. You can smile ironically."