by Adam McDowell
The Ultimatum Game works like this: You are given $100 and asked to share it with someone else. You can offer that person any amount and if he accepts the offer, you each get to keep your share. If he rejects your offer, you both walk away empty-handed.
How much would you offer? If it's close to half the loot, you're a typical North American. Studies show educated Americans will make an average offer of $48, whether in the interest of fairness or in the knowledge that too low an offer to their counterpart could be rejected as unfair. If you're on the other side of the table, you're likely to reject offers right up to $40.
It seems most of humanity would play the game differently. Joseph Henrich of the University of British Columbia took the Ultimatum Game into the Peruvian Amazon as part of his work on understanding human co-operation in the mid-1990s and found that the Machiguenga considered the idea of offering half your money downright weird — and rejecting an insultingly low offer even weirder.
"I was inclined to believe that rejection in the Ultimatum Game would be widespread. With the Machiguenga, they felt rejecting was absurd, which is really what economists think about rejection," Dr. Henrich says. "It's completely irrational to turn down free money. Why would you do that?"
It turns out the Machiguenga — whose number system goes: one, two, three, many — are not alone in their thinking. Most people from non-Western cultures introduced to the Ultimatum Game play differently than Westerners. And that is one clue that the Western mind differs in fundamental ways from the rest of humanity, according to Dr. Henrich. He and two other UBC researchers authored a paper shaking up the fields of psychology, cognitive science and behavioural economics by questioning whether we can know anything about humanity in general if we only study a "truly unusual group of people" — the privileged products of Western industrial societies, who just happen to make up the vast majority of behavioural science test subjects.
The article, titled "The weirdest people in the world?", appears in the current issue of the journal Brain and Behavioral Sciences. Dr. Henrich and co-authors Steven Heine and Ara Norenzayan argue that life-long members of societies that are Western, educated, industrialized, rich, democratic — people who are WEIRD — see the world in ways that are alien from the rest of the human family. The UBC trio have come to the controversial conclusion that, say, the Machiguenga are not psychological outliers among humanity. We are.
"If you're a Westerner, your intuitions about human psychology are probably wrong or at least there's good reason to believe they're wrong," Dr. Henrich says.
After analyzing reams of data from earlier studies, the UBC team found that WEIRD people reacted differently from others in experiment after experiment involving measures of fairness, anti-social punishment and co-operation, as well as visual illusions and questions of individualism and conformity.
Others punish participants perceived as too altruistic in co-operation games, but very few in the English-speaking West would ever dream of penalizing the generous. Westerners tend to group objects based on resemblance (notebooks and magazines go together, for example) while Chinese test subjects prefer function (grouping, say, a notebook with a pencil). Privileged Westerners, uniquely, define themselves by their personal characteristics as opposed to their roles in society.
Moreover, WEIRD people do not simply react to the world differently, according to the paper, they perceive it differently to begin with. Take the well-known Muller-Lyer optical illusion, which uses arrows to trick the viewer into thinking one line is longer than another, even if both are the same length. (See the diagram on this page.)
"No matter how many times you measure those lines, you can't cause yourself to see them as the same length," Dr. Henrich says. At least that's true for a Westerner. For some hunter-gatherers, the Muller-Lyer lines do not cause an illusion. "You do this with foragers in the Kalahari [Desert] and they just see the lines as the same length."
WEIRD people, the UBC researchers argue, have unusual ideas of fairness, are more individualistic and less conformist than other people. In many of these respects, Americans are the most "extreme" Westerners, especially young ones. And educated Americans are even more extremely WEIRD than uneducated ones.
"The fact that WEIRD people are the outliers in so many key domains of the behavioral sciences may render them one of the worst subpopulations one could study for generalizing about Homo sapiens," the authors conclude. "If the goal of the research program is to shed light on the human condition, then this narrow, unrepresentative sample may lead to an uneven and incomplete understanding."
In other words, we do not know what we thought we knew about the human mind. We only know about the mind of a particular, unusual slice of humanity.
The UBC researchers also found that 96% of behavioural science experiment subjects are from Western industrialized countries, which account for just 12% of the world's population. Sixty-eight percent were Americans. The United States is dominant in the field of psychology, accounting for 70% of all journal citations, compared with 37% in chemistry. Undergraduate students are often used to stand in for the entire species.
"This is a serious problem because psychology varies across cultures and chemistry doesn't," says Jonathan Haidt, a psychologist at the University of Virginia.
The paper argues that either many studies' conclusions have to be retested on non-WEIRD cultural groups — a daunting proposition in terms of resources — or they must be understood to offer insight only into the minds of rich, educated Westerners.
If WEIRD people are indeed weird, it is the Enlightenment and the Industrial Revolution that have made them so. In the example of the Muller-Lyer illusion, the UBC team hypothesizes that growing up in an industrial-era environment with plenty of 90-degree lines and carpentered edges led to WEIRD people's sense of vision being susceptible to the deception.
"We live in this world with police and institutions and pre-packaged food, TV, the Internet, watches and clocks and calendars. Our heads are loaded with all this information for navigating those environments. So we should expect our brains to be distorted," Dr. Henrich says.
North American behavioural scientists were aware of the issues raised by the paper. "It confirms something that many researchers knew all along but didn't want to admit or acknowledge because its implications are so troublesome," says Dr. Haidt of the University of Virginia, who was on a panel of academics who reviewed the article before publication.
Dr. Henrich says the UBC team expected stiff resistance to its ideas. But overall the paper has been well-received, says Dr. Haidt, although, of course, it has been read mostly by WEIRD academics. But how would the other 88% of humanity react? Would they be surprised to learn that rich Westerners are, in a word, weird?
"I don't think so," Dr. Henrich says.
Some psychologists doubt whether privileged Westerners actually are the odd people out. Cultural psychologist Will Bennis of Northwestern University applauds the UBC team's call to widen the spectrum of humanity studied by behavioural scientists, but he doubts whether a more cosmopolitan subject pool will sustain the idea that WEIRD people are "more unique, more distinct, more different from all the other populations that have been targets of research."
"Why do they look like outliers? Is it because they are more weird than other populations? Or is it something methodological that's making it look like they're outliers," Dr. Bennis asks.
He notes a human tendency, throughout history and across cultures, to regard one's own group as unique. "There's a lot of reasons why we might mistakenly assume that our group is special," he says. "The point isn't that our group is not special, it's that each group is special in its own unique way. As WEIRD psychologists ... we happen to know what's special about our own group and we happen to focus on that in our psychological research."
The WEIRD hypothesis does not throw out the whole idea of human behavioural and psychological universals. The UBC team remains confident that displays of pride and some aspects of mating, for example, will turn out to be pan-human characteristics.
The UBC researchers acknowledge the limits of what is known about WEIRD versus non-WEIRD populations. Because data comparing how people from different populations think is relatively hard to come by, the authors write, "we cannot accurately evaluate the full extent of how unusual WEIRD people are."
"This is, however, precisely the point. We hope research teams will be inspired to span the globe and prove our claims of non-representativeness wrong."