The next time you come face to face with a dog wagging its tail, you can make a quick determination on whether to reach out and pet it or step back in deference: check the tail-wag bias. If the wagging tail leans to the dog’s right, you’re safe; if the tail leans to the dog’s left, don’t move.

This tail-wagging bias was documented in a 2007 article in the journal Current Biology by Italian neuroscientist Giorgio Vallortigara and his veterinarian colleagues at the University of Bari. In an experiment, 30 mixed-breed dogs were each placed in a cage equipped with cameras that measured the asymmetrical bias (left or right) of tail wagging while the pooches were exposed to four stimuli: their owner, an unfamiliar human, a cat and an unfamiliar dominant dog. Owners elicited a strong right bias in tail wagging, and unfamiliar humans and the cat triggered a slight right bias. But the unfamiliar dominant dog (a large Belgian Shepherd Malinois) elicited a strong left bias in tail wagging. Why?

According to the researchers, because the left brain controls the right side of the body, and vice versa, the nerve signals cross the midline of the body and cause the dog’s tail to wag more to the right when its left brain is experiencing a positive emotion. This left-right distinction may be explained by the fact that birds, fish and frogs show left-brain/right-brain differences in approach-avoidance behavior, with the left brain associated with positive approach feelings and the right brain associated with negative avoidance feelings. Closer to evolutionary home, when chimpanzees are experiencing negative emotions, they tend to scratch themselves on the left side of their bodies, and left-handed chimps, whose right brain is dominant, tend to be more fearful of novel stimuli than right-handed chimps.

In humans as well, experiments have revealed that the left brain is associated with positive emotions such as love, attachment, bonding and safety. For example, electroencephalogram (EEG) studies of the brains of subjects who report positive emotions or are shown a funny video clip experience an increase in activity in the left frontal cortex, whereas reports of negative emotions and unpleasant video clips coincide with an increase in activity in the right frontal cortex. In addition, brain scans of subjects who are viewing a photograph of a cute baby show increased activity in the same left frontal cortex area; subjects looking at a photograph of a grotesquely deformed baby show increased activity in the same right frontal cortex area. Finally, bombarding the left frontal cortex of the brain with a strong magnetic field elicits a positive mood in human subjects, and the reverse elicits a negative mood.

Why would the brain show such differences in neural networks associated with emotions? Employing evolutionary theory, I would like to suggest that emotions interact with our cognitive thought processes to guide our behaviors toward the goal of survival and reproduction. University of Southern California neuroscientist Antonio R. Damasio, for example, has demonstrated the vital role that emotions play in decision making. At low levels of stimulation, emotions appear to have an advisory role, interacting with the more reason-oriented cortical regions of the brain. At medium levels of stimulation, conflicts can arise between these cortical reason centers and the brain’s deeper and evolutionarily older emotion centers. At high levels of stimulation, emotions can so overrun cortical cognitive processes that people can no longer reason their way to a decision and report feeling “out of control.” But why should we have evolved emotions at all?

Emotions are evolutionary proxies for getting us to act in ways that lead to an increase in reproductive success. If we think of the feeling of hunger as a very basic emotion, for example, a little bit of hunger may be perceived as pleasant, motivating us to seek and find food, whereas too much hunger becomes an unpleasant emotion when it goes unmet. In this homeostatic model, emotions act as a feedback mechanism to alert the brain when the body is out of balance. Positive emotions help us build enduring personal resources, such as problem-solving skills, coordination and social resources. Negative emotions, in contrast, help to protect us. Fear causes us to pull back and retreat from risks. Disgust directs us to push out and expel that which is bad for us. Anger leads us to fight back or to signal displeasure at the violation of a social agreement. Jealousy leads us to guard our mates against intruders in pair-bonded relationships.

Such studies indicate that often the evolutionary tail wags the emotional dog.

A review of Malcolm Gladwell’s Blink: The Power of Thinking without Thinking.

Anyone who does a lot of public speaking knows there are certain questions that inevitably arise from the audience in a Q&A session. In my case, lecturing on pseudoscience and the paranormal, I am almost always asked: What is my position on the afterlife? (“I’m for it”), have I ever encountered a mystery that science cannot explain? (“Paris Hilton”), and have I ever been skeptical of something that turned out to be real? For this final question I have a serious answer: intuition.

As a skeptical scientist, I have always treated with disdain the notion that one can intuit a truth about reality. Scientists should employ the logic of Mr. Spock, the deductive reasoning of Mr. Holmes, and the rational calculus of Mr. Data. Hunches, guesses, insights, feelings, and intuitions lead to misdirection and error. Thinking things through rationally and systematically is the royal road to reality.

Well, I was wrong. It turns out there’s a lot more to thinking than meets the experimental eye, and Malcolm Gladwell has penned an absolutely delightful summary of all the important research in the study of intuition. His title, Blink, is apt, for we humans have a remarkable — and heretofore unproven — capacity for making judgments in the metaphorical blink of an eye that are often superior to those we might have made had we taken the time to assess all possible variables.

Gladwell begins with the fascinating story of how the Getty Museum got taken by a forged Kouros, a sculpture of a youth allegedly carved in 6th-century B.C. Greece. Despite an intuitive hunch many of its experts had that there was something about the piece that was not quite right, there was no smoking gun of fakery any one could identify. So the artwork was purchased, and only later was it exposed as a fake. The best assessment of whether a work of art is a forgery, it turns out, is the first impression an art expert has on seeing it, not necessarily a battery of scientific tests. For example, one of the art experts — Thomas Hoving, the former director of New York’s Metropolitan Museum of Art — later recalled that the first word that popped into his mind when he saw the Kouros was “fresh.” Although he could not say precisely what about the statue was fresh, it was a general feeling he had about it. “I had dug in Sicily where we found bits and pieces of these things. They just don’t come out looking like that. The Kouros looked like it had been dipped in the very best café au lait from Starbucks.”

What is happening here is nonrational (not irrational) analysis at a level below conscious awareness. Students who view three 10-second video clips of a professor, for example, give roughly the same ratings of that professor’s effectiveness as those students who actually took the course. (This may also mean that student evaluations are actually based on first impressions rather than extensive analysis.) The same effect — called “thin slicing” — can be seen in dating, where first impressions are everything, as is well known by those who have tried “speed dating,” a trendy way to meet people, in which each of multiple “dates” in one evening lasts only six minutes. Thin slicing is intuitive thinking, “thinking without thinking” as Gladwell puts it. That’s not quite right, however, as I suspect it is more of a subtle, unconscious (or subconscious) form of thinking that we just don’t know that much about as yet. We are collecting data about a person or situation, and that data is being analyzed somewhere in the brain. How precisely that is being done remains a mystery.

Evaluating whether someone is trustworthy or not, or whether someone is lying or telling the truth, is more accurately done by intuitive “feel” in a brief interaction than by subjecting them to a polygraph test. The best predictor of how well a psychotherapist or marriage counselor will work for you is the impression you have of that person in the first five minutes of the first session. University of Washington psychologist and marriage counselor John Gottman, who has reversed the process, can predict with 95% accuracy whether a marriage will last or not after observing the couple for only one hour. Contempt for one’s spouse, for example, is a powerful predictor of a doomed marriage, and rolling one’s eyes when one’s spouse is speaking, is a proxy for contempt. A lot can be read in the blink of an eye.

We are especially good at snap judgments when it comes to human relations, because we evolved as a social primate species living in small tribes in which social relations were extremely important. We needed (and still need) to know whom we can trust and whom we cannot trust; in the prehistoric world of our Paleolithic environment we had only our wits and intuitions, the “sense” or “feeling” we had for someone’s trustworthiness, to rely on. The social calculus was not the slow and systematic logic of analysis; it was (and is) the subtle and fast feeling of a felt emotion. That “feeling” is the expression of an internal computation whose consequences are important.

This explains the interesting results of an experiment conducted by the psychologist Samuel Gosling. He rated 80 subjects on the “Big Five” personality scale (extraversion, agreeableness, conscientiousness, emotional stability, and openness to experience). He found a high correlation with similar ratings of the subjects done by their best friends — no surprise. But then he sent total strangers into the dorm rooms of the subjects and gave them 15 minutes to answer questions about the person who lived there. The strangers were not as good as the best friends in evaluating extraversion and agreeableness, but on conscientiousness, emotional stability, and openness to experience, the strangers knew the subjects better than their best friends!

Some of the research findings on what might be called “the blink effect,” so well encapsulated by Gladwell, are startling. The best predictor of whether a physician will be sued for malpractice is not the doctor’s training, credentials, or track record, but a subjective evaluation by observers of short clips of conversation between doctor and patient. Physicians who seem warm and empathetic — traits that can be sensed in a blink — are less likely to be sued by their patients, regardless of the number of errors they commit. As one lawyer explained it, “In all the years I’ve been in this business, I’ve never had a potential client walk in and say, ‘I really like this doctor, and I feel terrible about doing it, but I want to sue him.’ We’ve had people come in saying they want to sue some specialist, and we’ll say, ‘We don’t think that doctor was negligent. We think it’s your primary care doctor who was at fault.’ And the client will say, ‘I don’t care what she did. I love her, and I’m not suing her.’”

Unfortunately, in what Gladwell calls “the dark side of blink,” we sometimes make snap assessments of people based on inappropriate criteria, such as their gender or race. Research with the Implicit Association Test has shown that we form connections between things faster when there is already an association, such as between “female” and “laundry,” “home,” “kitchen,” “housework,” and “babies”; and between “male” and “professional,” “merchant,” “capitalist,” “corporation,” and “entrepreneur. Even more sinister are the associations of African-American or European-American with such adjectives as “hurt,” “evil,” “glorious,” and “wonderful.” “It turns out that over 80 percent of all those who have ever taken the test end up having pro-white associations,” Gladwell explains, “meaning that it takes them measurably longer to complete the test when they are required to link good things with black people than when they are required to link bad things with black people.”

Gladwell took the test and was rated as having “moderate automatic preference for whites”; “but then again, I’m half black,” he points out. Meaning what? “What it means,” he concludes, “is that our attitudes towards things like race or gender operate on two levels. First of all, we have conscious attitudes. These are our stated values, which we use to direct our behavior deliberately.” The IAT, on the other hand, measures “our racial attitudes on an unconscious level — the immediate, automatic associations that tumble out before we’ve even had time to think. We live in North America, where we are surrounded every day by cultural messages linking white with good.”

Blink is packed with examples of such intuitive processes, a thoughtful and thought-provoking look into both the light tunnel and the dark well of our minds. But I wish to praise it on another plane as well.

There are, roughly speaking, three levels of science writing in our culture: (1) technical (peer-reviewed papers, monographs, and university press books written by and for professional scientists); (2) popular professional (essays and articles in popular magazines and trade press books written by scientists for both scientists and moderately informed general readers — Stephen Jay Gould, Richard Dawkins, and Jared Diamond come to mind); (3) popular general (essays, articles, and books by journalists and science writers for completely uninformed readers).

We live in the Age of Science, and all three levels are vital for the dispersal of scientific knowledge to an educated democracy. Sadly, too many professional scientists think level one is the only legitimate form of science writing, and that anything else is simply “dumbing down.” For his presentation of science to hundreds of millions of people, the astronomer Carl Sagan was slammed by his peers, denied tenure at Harvard, and rejected by the National Academy of Science. Yet he never stopped producing peer-reviewed articles, averaging one a month for his entire career.

Gladwell is presenting science at level three, where it is most needed, and where good writing is most vital. He has the ability to synthesize a large body of scientific data into a highly readable, page-turning narrative, and to convert the raw numbers of research and statistics into meaningful facts for our personal lives. I thought he did this brilliantly with The Tipping Point, and I think he does it even better in Blink. For this feat all of us in the scientific community should be grateful, because the craft of writing good science is just as important as the skill of producing good science.

(Little, Brown & Company, 2005, ISBN 0316172324)
This review was originally published in New York Sun.

Stardate: 1672.1. Earthdate: October 6, 1966. Star Trek, Episode 5, “The Enemy Within.”

Captain James T. Kirk has just beamed up from planet Alpha 177, where magnetic anomalies have caused the transporter to malfunction, splitting Kirk into two beings. One is cool and rational. The other is impulsive and irrational. Rational Kirk must make a command decision to save the crew, but he is paralyzed with indecision, bemoaning to Dr. McCoy: “I can’t survive without him. I don’t want to take him back. He’s like an animal — a thoughtless, brutal animal. And yet it’s me!”

This psychological battle between intellect and intuition was played out in almost every episode of Star Trek in the characters of the ultrarational Mr. Spock and the hyperemotional Dr. McCoy, with Captain Kirk as the near perfect synthesis of both. Thus, I call this balance the Captain Kirk Principle: intellect is driven by intuition, intuition is directed by intellect.

For most scientists, intuition is the bête noire of a rational life, the enemy within to beam away faster than a phaser on overload. Yet the Captain Kirk Principle is now finding support from a rich emerging field of scientific inquiry brilliantly summarized by Hope College psychologist David G. Myers in his book Intuition: Its Powers and Perils (Yale University Press, 2002). I confess to having been skeptical when I first picked up the book, but as Myers demonstrates through numerous well-replicated experiments, intuition—“our capacity for direct knowledge, for immediate insight without observation or reason” — is as much a component of our thinking as analytical logic.

Nalini Ambady and Robert Rosenthal of Harvard University, for example, discovered that evaluations of teachers by students who saw a mere 30-second video of the teacher were remarkably akin to those of students who had taken the course.

Even three two-second video clips of the instructor yielded a striking 0.72 correlation with the course students’ evaluations.
Research consistently shows how so-called unattended stimuli can subtly affect us. At the University of Southern California, Moshe Bar and Irving Biederman flashed emotionally positive images (kitten, romantic couple) or negative scenes (werewolf, corpse) for 47 milliseconds immediately before subjects viewed slides of people. Although subjects reported seeing only a flash of light for the initial emotionally charged pictures, they gave more positive ratings to people whose photographs had been associated with the positive ones — so something registered.

Intuition is not subliminal perception; it is subtle perception and learning — knowing without knowing that you know. Chess masters often “know” the right move to make even if they cannot articulate how they know it. People who are highly skilled in identifying “micromomentary” facial expressions are also more accurate in judging lying. In testing college students, psychiatrists, polygraphists, court judges, police officers and Secret Service agents on their ability to detect lies, only the agents, trained to look for subtle cues, scored above chance.

Most of us are not good at lie detection, because we rely too heavily on what people say rather than on what they do. Subjects with damage to the brain that renders them less attentive to speech are more accurate at detecting lies, such as aphasic stroke victims, who were able to identify liars 73 percent of the time when focusing on facial expressions. (Nonaphasic subjects did no better than chance.) We may even be hardwired for intuitive thinking: damage to parts of the frontal lobe and amygdala (the fear center) will prevent someone from understanding relationships or detecting cheating, particularly in social contracts, even if he or she is otherwise cognitively normal.

Although in science we eschew intuition because of its many perils (also noted by Myers), we’d do well to remember the Captain Kirk Principle, that intellect and intuition are complementary, not competitive. Without intellect, our intuition may drive us unchecked into emotional chaos. Without intuition, we risk failing to resolve complex social dynamics and moral dilemmas.

As Dr. McCoy explained to Kirk: “We all have our darker side — we need it! It’s half of what we are. It’s not really ugly, it’s human. Your strength of command lies mostly in him.”