Monday, August 25, 2008

The Brain and the Human Condition

Human: The Science Behind What Makes Us Unique

By: Michael S. Gazzaniga, Ph.D.

In his new book, Michael S. Gazzaniga explores what it means to be human. In this excerpt from Chapter 3, he explores the evolutionary and social reasons for why we deceive one another—and ourselves.

Humans possess skills ranging from manual dexterity to language to empathy—skills virtually unknown in the rest of the animal world. We have by far the most complex social system, one that has caused our brain to develop and, in turn, is further developed by the brain. Our decisions are complicated by moral values, our understanding of the world by our self awareness. A large body of research is asking what happened in our evolutionary journey that produced the unique organ that is the human brain.

In his previous book, The Ethical Brain, Michael S. Gazzaniga—often called the father of cognitive neuroscience— looked into the brain basis for ethics, as well as new concerns that arise as we learn more about what it is to be human. Now, in Human: The Science Behind What Makes Us Unique, Gazzaniga expands this investigation to touch all aspects of the human mind, explaining how our brains developed the special structures that set us apart from animals and those that make us the same.

In this excerpt from Human, Gazzaniga delves into our past to uncover the reasons we lie. The ability to purposely deceive both ourselves and others has an important role in human interaction, going beyond the animal forms of deception that allow the chameleon to blend in with its surroundings. After all, no one wants to be told that those pants really do make them look fat.


From Human: The Science Behind What Makes Us Unique, by Michael S. Gazzaniga. Copyright © 2008 by Michael Gazzaniga. By permission of ECCO, an imprint of HarperCollins Publishers.

Detecting Cheaters

[Leda] Cosmides1 also came up with an experiment that she thinks demonstrates that the human mind has a special module designed to detect individuals who cheat in social exchange situations. She uses the Wason Test,* which asks you to look for potential violations of a conditional rule: if P, then Q. Many forms of this test have been devised to ascertain whether or not humans have specialized cognitive machinery for social exchange. Let’s see how you do with it:

There are four cards on a table. Each card has a letter on one side and a number on the other. Currently you can see R, Q, 4, and 9. Turn over only those cards that you need to in order to prove whether the following rule is true or false: If a card has an R on one side, then it has a 4 on the other. Got it? What’s your answer?

The answer is R and 4. OK, now try this one:

There are four people sitting at a table. One is sixteen, the second is twenty-one, the third is drinking Coke, and the fourth is drinking beer. Only those over twenty-one can drink beer legally. Who should the bouncer check to make sure the law isn’t being broken? That one is easier isn’t it? The answer is the sixteen-year-old and the beer drinker.

Cosmides has found that people have a hard time with the first type of question; only 5 to 30 percent of people get this one right, whereas with the second one, 65 to 80 percent of people get it right—not just at Stanford where she first tried it, but all over the world, from the French to the Shiwiar of the Ecuadorian Amazon, and not just adults, but three-year-olds as well.2 Whenever the content of a problem asks you to look for cheaters in a social exchange situation, people find it simple to solve, whereas if it is posed as a logic problem, it is more difficult to solve.

After many more experiments across cultures and age groups, Cosmides has found in addition that cheater detection develops at an early age, operates regardless of experience and familiarity, and detects cheating but not unintentional violations. She thinks that this cheater detection ability is a component of a universal human nature, designed by natural selection to produce an evolutionally stable strategy for conditional helping.

There is even neuroanatomical evidence. This comes from a patient, R.M., who has focal brain damage that has caused impairment in his cheater detection, but who has entirely normal reasoning on similar tasks that do not involve social exchange.3 Cosmides says, “As humans, we take for granted the fact that we can help each other by trading goods and services. But most animals cannot engage in this kind of behavior—they lack the programs that make it possible. It seems to me that this human cognitive ability is one of the greatest engines of cooperation in the animal kingdom.”1

In social contract situations, people rated cheaters more important to remember than cooperators, looked at cheaters longer, remembered their faces better, and were more likely to remember social contract information about them.

We are not the only ones who can detect cheaters in social exchanges. It has been shown to exist to a limited degree in brown capuchin monkeys, in experiments done by Sarah Brosnan and Frans de Waal.4 However, animals involved in reciprocal exchange make approximations. Humans want to be sure they are giving and getting the equivalent amount; approximations won’t suffice. Indeed, Marc Hauser at Harvard University thinks that our mathematical abilities evolved with the emergence of social exchange systems.5

Cheating the Cheaters

 Can you cheat the cheater detection system? Probably not, as Dan Chiappe, a psychologist at the University of Toronto, has found. He showed that in social contract situations, people rated cheaters more important to remember than cooperators, looked at cheaters longer, remembered their faces better, and were more likely to remember social contract information about them.6

When cheaters have been detected, there are two things that can be done with them: Either you avoid them, or you punish them. Isn’t it easier just to avoid them? To punish a cheater costs the punisher time and effort. What’s to be gained? Recently Pat Barclay, from Cornell University, has done a laboratory study showing that in games with repeated encounters, players who punish cheaters gain trust and respect and are thought of as being group focused. The benefits of this increase in good reputation (which, you remember, is a fitness indicator for sexual selection) can offset the costs of being a punisher, and could be a possible explanation for how the psychological mechanisms of altruistic behavior evolved.7 Better not do anything that might lead to one of your competitors’ getting a better rep. What a stroke of luck that you saw Don with that sophisticated-looking blonde at the racetrack. Everyone wonders what he does on his days off. That tidbit ought to be a hot commodity in the world of gossip exchange back at the office, but how will you know if what you get back is true? If you can detect cheaters, does that mean you’ll know if someone is lying? Not really. That comes with reading facial expressions and body language. But I’m glad you brought that up because . . .

Intentional Deception

Although deception is known throughout the animal world, such as the piping plover that feigns injury to lead predators away from its nests,8 intentional deception may be limited to the great apes.9 And humans are the masters of deception. It is ubiquitous and begins in the morning when women put on makeup (to make themselves more beautiful or appear younger) and perfume (to mask their own odor). Women have been using jewelry, hair color, and makeup for eons. One has only to cruise through the Egyptian section of the Louvre. Men are no strangers to deception either. They put on deodorant and brush their thin hair across their bald spots (as if that deceives anyone) or plop on their toupees and head out to their cars that they had to buy on credit.

Can you imagine a world where no one lied? It would be awful. Do you really want to know the answer to “Hi, how are you doing today?” Or hear “I’ve noticed that those five pounds that you’ve put on are all on your chin”? Lies are used for self- promotion in job interviews (“Sure, I know how to do that”), and when meeting new people (“This is your daughter? Isn’t she the sweetest thing!” rather than Rodney Dangerfield’s comment, “Now I know why tigers eat their young”).10 They’re used when meeting potential mates (“Of course I’m a natural blonde”).11

From 100 percent of high school students who rank themselves as having a higher-than-average ability to get along with others (a mathematical impossibility) to 93 percent of college professors who rank themselves above average at their work, self-deception is in play. We not only lie to each other, we lie to ourselves. From 100 percent of high school students who rank themselves as having a higher-than-average ability to get along with others (a mathematical impossibility) to 93 percent of college professors who rank themselves above average at their work, self-deception is in play.12 Or how about “I get plenty of exercise” and “My kid would never do that.” To be a good liar, it helps not to know that you are lying or, in the case of psychopaths, not to care. In fact children are taught to lie by their parents (“Tell Grandma how much you love the lederhosen” and “Don’t tell Sammy he is fat”) and by teachers (“I don’t care if you think Joe is dumb, it is not nice to say so”).

How do we tell if someone is lying? Do we really want to know? And why do we lie to ourselves?

How Do We Tell If Someone Is Lying?

While gossiping and determining if we think the information we are getting is true, we also read facial expressions. Face perception is probably the most developed visual skill in humans and obviously plays a major role in social interactions. It has long been thought that face perception is mediated by a specialized system in the human brain, and we now know that different parts of the brain mediate different types of face perception. The pathways that perceive identity are different from those that perceive movement and expressions.

Beginning soon after birth, babies prefer to look at faces rather than other objects.13 After the age of seven months, we begin to respond appropriately to specific expressions.14 Thereafter, face perception provides tons of information that greases social interaction. From the visual appearance of faces, one can access information about another person’s identity, background, age, gender, mood, interest level, and intentions. We can notice what they are looking at and check it out too, and also understand their speech better by lip- reading.15

We are not alone in the ability to recognize individual faces. Chimpanzees and rhesus monkeys are also able to do so.15 Contrary to what has previously been observed, recent dissection has shown that chimpanzees and humans have a nearly identical facial anatomy16 and a full range of facial expressions. Lisa Parr at Emory University has done some studies that demonstrate the ability of chimps to match photographic facial expressions with emotional scenes in videos.17 So we share with the chimps two components of gossiping and social exchange—recognizing with whom we are dealing and being able to read emotions from facial expressions—but will that help us in recognizing liars? Well, there is a whole range of facial and body movements that are associated with deception, which brings us back to our man Machiavelli.

Paul Ekman, at the University of California, San Francisco, has done more for the study of facial expression than anyone else. It was a lonely business when he started his studies, because everyone else—except Darwin, of course, and an eighteenth- century French neurologist named Duchenne de Boulogne—had avoided the topic. Ekman, through years of research, has established that facial expressions are universal18 and that there are specific expressions for specific emotions. When an individual is lying, the higher the stakes are, the more emotions (such as anxiety or fear) he is feeling.19 These emotions are leaked to the face20 and voice tone.21 And here is one of the benefits of true self-deception: If you don’t know you are lying, your facial expressions won’t give you away.

Ekman has studied people’s ability to detect liars, and it is pretty pathetic. Most people aren’t very good at it, even though they may think they are (once again deceiving themselves). They perform at the same rate as chance guessing. However, he has found some professionals to be good at it: Secret Service agents are the best, and next best are some psychotherapists. Out of twelve thousand people whom he has tested, he found only twenty who were naturally excellent lie detectors!22 One problem inherent in reading facial expressions is that one reads the emotion but does not necessarily understand the reason for the emotion and so misinterprets it. We will learn more about this in later chapters. You may realize that a person is scared and think it is because he is lying to you and is frightened that you will figure that out, but it could be that he is scared because he didn’t lie and is being falsely accused and he thinks that you won’t believe him.

Of course not all deception is nefarious. Out of politeness, people will often act as if they are enjoying themselves when they are not, such as complimenting you on the fish dish when in reality fish makes them gag.Of course not all deception is nefarious. Out of politeness, people will often act as if they are enjoying themselves when they are not, such as complimenting you on the fish dish when in reality fish makes them gag. Or they are laughing at that really bad joke that you have already told too many times before. These are small-stakes lies without major repercussions.

People learn to manage their expressions, but Ekman has found microexpressions that result from trying to conceal emotions. Most people don’t see them, but you can learn to spot them. Fabricated expressions can also be hard to spot. For instance, the false smile: There are two muscles principally involved in real smiling, the zygomaticus major, which pulls the corners of the mouth up, and the orbicularis oculi pars lateralis, which, along with pulling up the cheeks and causing crow’s-feet, also pulls down the lateral border of the eyebrow. The orbicularis oculi muscle is not under voluntary control, so that in a fake smile the lateral border of the eyebrow does not depress, although a fully contracted zygomaticus can push the cheeks up to form crow’s-feet.

If we are good at spotting cheaters in social exchange, why do we find it hard to spot liars? Lying has become prevalent in the population, so wouldn’t mechanisms of detection have evolved? Ekman offers several explanations. First, he suggests that in the environment in which we evolved, lying wasn’t as prevalent because there were fewer opportunities. People lived openly in groups. The lack of privacy would have made the chances of detection high, and discovery would have been made by direct observation of behavior rather than having to rely on judgments of demeanor. Second, uncovered lies would have resulted in a bad reputation. Today, our environment is very different. Opportunities to lie abound, and we live behind closed doors. You can escape from a bad reputation, although it may be costly, by changing jobs, towns, countries, or spouses, and we haven’t been prepared by evolution to detect lies from demeanor. So why haven’t we learned how to detect them if we don’t have the power innately? Perhaps because our parents teach us not to identify their lies, such as stories to cover up sexual activity and who knows what all. It may be that we also prefer not to catch liars, because being suspicious rather than trusting makes relationships difficult to establish and keep. Or we may want to be misled because we have a stake in not knowing the truth. The truth may set you free, but it may also set you free with four kids and no income. Often the reason is politeness: What we are told is all that the teller wants us to know, and we don’t steal information that is not given to us.

But perhaps it is language, as it has evolved recently in humans, that is the problem. Understanding and interpreting language is a conscious process that involves much cognitive energy. If we are concentrating on what is being said, rather than letting visual perceptions and vocal clues register in our conscious brain, we may be lessening our detective powers. Gavin de Becker, in his book The Gift of Fear,23 advises people to trust the phenomenon that he defines as “knowing without knowing why.” He is an expert in predicting violent behavior, and he has found that most victims of violence have received warning signs without realizing it. Has our social training taught us not to detect deception? Do we reinterpret what we actually see? There is more work to be done.

Lying to Ourselves

Isn’t lying to ourselves counterproductive? As the saying goes, if you can’t trust yourself, then whom can you trust? Remember our cheater detector in social exchange? It pays to be cooperative, while being vigilant for cheaters. But you really don’t have to be cooperative. You just have to appear cooperative. All you need is a good rep. You don’t actually have to deserve it.

You mean being a hypocrite, right? Hypocrites make my blood boil.

Not so fast. Everyone (except for me, of course) is a hypocrite. It apparently is just easier to see from the outside than the inside. As we just learned, to pull this off, it helps not to consciously know that you are pulling a fast one, because then you will have less anxiety and thus less chance of getting busted.

Dan Batson at the University of Kansas has done a series of experiments24,25 with rather shocking results. Students were given the opportunity to assign themselves and another student (actually fictitious) to different tasks. One task was more desirable (the chance to earn raffle tickets). The other task had no chance to earn raffle tickets and was described as boring. The students were told that the other participant would think the assignment was made by chance. They were also told that most participants thought that flipping a coin was the fairest way to assign the tasks, and a coin was provided for participants to flip if they wished. After the experiment, virtually all participants said that either assigning the other participant the better task or using the coin flip was more moral. Yet only about half flipped the coin. Of the nonflippers, 80 to 90 percent assigned themselves the better task and, contrary to the laws of probability, the same was true among those who flipped the coin. The students who flipped the coin all rated themselves as being more moral than the nonflippers, even when they fiddled with the results.

This outcome was replicated in numerous studies, even when the coin was labeled to avoid ambiguities in the coin toss. Some participants flipped the coin to appear fair, yet still served self- interest by ignoring the results and giving the better task to themselves—and still rated themselves as being more moral for simply having tossed the coin! That is called moral hypocrisy. The results were duplicated even when the students were told that after their decision they would have to tell the other participant how they arrived at it. With one discrepancy, more flipped the coin (75 percent) and reported this was how they had made the decision; however, the percent of flippers who gave themselves the better task remained the same. Batson states, “The benefits to oneself of moral hypocrisy are obvious: One can reap the material rewards of acting selfishly and also garner the social and self rewards of being seen and seeing oneself as upstanding and moral.”

Thus, those with a greater sense of moral responsibility did not show signs of greater moral integrity; they actually showed signs of greater hypocrisy! Participants who had scored highly on various moral responsibility tests were more likely to flip the coin, yet among coin flippers, the high moral scorers were no less likely to assign themselves the better task than were those who scored low. Thus, those with a greater sense of moral responsibility did not show signs of greater moral integrity; they actually showed signs of greater hypocrisy! They were more likely to appear moral (flip the coin) but no more likely to actually be moral (allow the coin flip to determine the task assignment).

The only time participants stopped cheating with the coin flip (and they all did) was when they made their decision while sitting in front of a mirror. Apparently, having to face the discrepancy between one’s stated moral standard to be fair versus unfairly ignoring the result of the coin flip was too much. Those who wished to appear moral had to actually be moral. Maybe we need more mirrors. That might help with the increasing obesity problem, too.

OK, so we lie to ourselves and have a difficult time spotting other liars. This isn’t good news for your gossip exchange quest. You may need to take one of Paul Ekman’s classes on how to spot liars, but in the meantime, at least you can watch eyebrows and know that your coworkers aren’t going to be good at spotting your lies, unless the high stakes at the office make you a little more anxious.


*P. C. Wason, “Reasoning about a rule,” Quarterly Journal of Experimental Psychology A 20 (1968): 273–81.

1. Hutsler, J.J., and Galuske, R.A.W. (2003). Hemispheric asymmetries in cerebral cortial networks. Trends in Neuroscience 26: 429–35.

2. Ramón y Cajal, S. (1990). The cerebral cortex. In New Ideas on the Structure of the Nervous System in Man and Vertebrates (pp. 35–72). Cambridge, MA: MIT Press.

3. Elston, G.N., andRosa, M.G.P. (2000). Pyramidal cells, patches and cortical columns: A comparative study of infragranular neurons in TEO, TE and the superior temporal polysensory area of the macaque monkey. Journal of Neuroscience 20:RC117:1–5.

4. Hutsler, J.J., Lee, D.-G., and Porter, K.K. (2005). Comparative analysis of cortical layering and supragranular layer enlargement in rodent, carnivore, and primate species. Brain Research 1052: 71–81.

5. Caviness, V.S.J., Takahashi, T., and Nowakaowski, R.S. (1995). Numbers, time and neocortical neurogenesis: A general developmental and evolutionary model. Trends in Neuroscience 18: 379–83.

6. Hutsler, J.J., Lee, D.-G., and Porter, K.K. (2005). Comparative analysis of cortical layering and supragranular layer enlargement in rodent, carnivore, and primate species. Brain Research 1052: 71–81.

7. Darlington, R.B, Dunlop, S.A., and Finlay, B.L. (1999). Neural development in metatherian and eutherian mammals: Variation and constraint. Journal of Comparative Neurology 411: 359–68.

8. Finlay, B.L., and Darlinton, R.B. (1995). Linked regulartieis in the development and evolution of mammalian brains. Science 268: 1578–84.

9. Rakic, P. (1981). Developmental events leading to laminar and areal organization of the neocortex. In Schmitt, F.O, Worden, F.G., Adelman, G., and Dennis, S.G. (eds.), The Organization of the Cerebral Cortex (pp. 7-28). Cambridge, MA: MIT Press.

10. Rakic, P. (1988). Specification of cerebral cortical areas. Science 241: 170–76.

11. Ringo, J.L., Doty, R.W., Demeter, S. and Simard, P.Y. (1994). Time is of the essence: A conjecture that hemispheric specialization arises from interhemispheric conduction delay. Cerebral Cortex 4: 331–34.

12. Hamilton, C.R., and Vermeire, B.A. (1988) Complementary hemisphere specialization in monkeys. Science 242: 1691–94.

13. Cherniak, C. (1994). Component placement optimization in the brain. Journal of Neuroscience 14: 2418–27.

14. Allman, J.M. (1999) Evolving brains. Scientific American Library Series, No. 68. New York: Scientific American Library.

15. Hauser, M., and Carey, S. (1998). Building a cognitive creature from a set of primitives: Evolutionary and developmental insights. In Cummins, D., and Allen, C. (eds.), The Evolution of the Mind (pp. 51–60). New York: Oxford University Press.

16. Funnell, M.G., and Gazzaniga, M.S. (2000). Right hemisphere deficits in reasoning processes. Cognitive Neuroscience Society Abstracts Supplements 12: 110.

17. Rilling, J.K., and Insel, T.R. (1999). Differential expansion of neural projection systems in primate brain evolution. NeuroReport 10: 1453–59.

18. Rizzolatti, G., Fadiga, L., Gallese, V., and Fogassi, L. (1996). Premotor cortex and the recognition of motor actions. Cognitive Brain Research 3: 131–34.

19. Rizzolatti, G. (1998). Mirror neurons. In Gazzaniga, M.S., and Altman, J.S. (eds.), Brain and Mind: Evolutionary Perpectives (pp. 102–10). HFSP workship reports 5. Strasbourg: Human Frontier Science Project.

20. Baron-Cohen, S. (1995). Mindblindness. An Essay on Autism and Theory of Mind. Cambridge, MA: MIT Press.

21. Watanabe, H., et al. (2004) DNA sequence and comparative analysis of chimpanzee chromosome 22. Nature 429: 382–88.

22. Vargha-Khadem, F., et al. (1995). Praxic and nonverbal cognitive deficits in a large family with a genetically transmitted speech and language disorder. Proceedings of the National Acedemny of Sciences 92: 930–33.

23. Fisher, S.E., et al. (1998) Localization of a gene implicated in severe speech and language disorders. Nature Genetics 18: 168–70.

24. Lai, C.S., et al. (2001). A novel forkhead=domain gene is mutated in severe speech and language disorder. Nature 413: 519–23.

25. Shu, W., et al. (2001). Characterization of a new subfamily of winged-helix/forkhead (Fox) genes that are expressed in the lung and act as transcriptional repressors. Nature 418: 869–72.

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Scientific Advisory Board
Joseph T. Coyle, M.D., Harvard Medical School
Kay Redfield Jamison, Ph.D., The Johns Hopkins University School of Medicine
Pierre J. Magistretti, M.D., Ph.D., University of Lausanne Medical School and Hospital
Helen Mayberg, M.D., Icahn School of Medicine at Mount Sinai 
Bruce S. McEwen, Ph.D., The Rockefeller University
Donald Price, M.D., The Johns Hopkins University School of Medicine
Charles Zorumski, M.D., Washington University School of Medicine

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