Good Reasons for Bad Feelings

by Randolph M. Nesse

  I asked about his parents’ relationship, his early life and previous relationships, and symptoms of other disorders but found nothing relevant. So we started cognitive behavioral therapy to try to correct his irrational thoughts. He made little progress. He insisted that his girlfriend was getting ready to leave, so we reassessed his problem.

  I now knew him well enough to ask him again about a common cause of pathological jealousy; “No,” he said, “I’m not having an affair, why would you think that?” However, when I asked again if he had any reason to suspect that his girlfriend might be having an affair, he said, “No, not at all. When she stays out, it is only with her best friend.” “How late does she stay out?” I asked. “Well,” he said, “she is with me at least five or six nights a week, but sometimes she stays out all night.” “And she swears it is just with her girlfriend?” I asked. “Oh, it’s not a girlfriend,” he said. “It is her best friend, a guy she has known for practically her whole life. They are just friends.” I paused to take this in and then said quietly, “We need to talk.”

  Sexual jealousy is an especially nasty emotion. In the 1960s, many people living in communes tried to eradicate it, advocating free love on the assumption that jealousy was a social convention that could be set aside. None of those communes survived. Despite all attempts to suppress it, jealousy grows back like a weed. It has dire effects on relationships. The expert on evolution and jealousy, David Buss, reports that 13 percent of all homicides are committed by a spouse.19 Of homicide victims in the United States from 1976 to 2005, 34 percent of women, but only 2.5 percent of men, were killed by an intimate partner. Murder is dramatic, but the everyday scourge of accusations, violence, and relationships ruined by jealousy is pervasive. Why hasn’t natural selection eliminated this awful emotion?

  Imagine two men, one with a tendency for jealousy when he senses his partner straying, another who is mellow with whatever goes down. Which one would have more children? The mellow one might well have a happier life, but his partner would be at a higher-than-average risk of becoming pregnant by someone else. That would make her infertile during the pregnancy and for several years more if she breastfeeds the baby. So men who lack jealousy tend to have fewer children than men whose jealousy—obnoxious, dangerous, and aversive as it is to all parties and society—makes such pregnancies less likely. If only emotions always benefited us! Alas, they were shaped to benefit our genes.

  Remedial Education

  As the utility of emotions became more obvious, I began to worry that my efforts to eliminate anxiety and depression might be like prescribing cough medicine to treat pneumonia. Renewed recognition of my ignorance about emotions aroused new emotions: embarrassment, confusion, low self-esteem, and, thankfully, curiosity. They were effective motivators. I examined my psychiatry textbooks more carefully. Of the 4,500 pages in the most widely used psychiatry textbook, normal emotions get only half a page.20 But hundreds of other books and articles describe emotions in detail. I embarked on a project to study them.

  After a month, I felt like a mountain climber pulling up over a ledge, expecting to be at the peak, only to discover higher peaks looming in the distance. After six months and ledge after ledge, I had had it. Instead of a clear view from a commanding peak, I saw a foggy landscape of jumbled facts and clashing factions. I found nothing remotely like a periodic table of the emotions. Instead, most writings about emotions rehashed debates that had persisted for decades or centuries. How many basic emotions are there? Four? Seven? Thirteen? Or are emotions better described as positions on continuous dimensions, such as positive ←→ negative, and aroused ←→ calm? Which aspect of emotions is primary: Physiology, thinking, feeling, facial expression, or behavior? What is the function of anger? Of sadness? And, most fundamental of all, what are emotions? Scores of books and articles offered conflicting answers.21,22,23,24,25,26,27,28,29,30,31

  In frustration, I turned to William James and his classic 1890 book, The Principles of Psychology.

  As far as “scientific psychology” of the emotions goes, I may have been surfeited by too much reading of classic works on the subject, but I should as lief read verbal descriptions of the shapes of the rocks on a New Hampshire farm as toil through them again. They give one nowhere a central point of view, or a deductive or general principle. They distinguish and refine and specify in infinitum, without ever getting on to another logical level.32

  It was satisfying to find such good company but discouraging to realize how little progress had been made in a hundred years. It is not for any lack of effort by smart people. If a periodic table of the emotions existed, the legions of emotions researchers would have found it. Unanswerable questions often turn out to be wrong questions. Does the object of the search even exist? What if emotions are organically complex in ways that make any simple description a gross misrepresentation? What if emotions are not at all like the components of a designed machine? Who had taken an evolutionary approach to emotions?

  I turned first to Charles Darwin’s book The Expression of Emotions in Man and Animals.33 It emphasizes the similarities of emotional expression in humans and other animals. Many emotion experts see it as a touchstone,34 but it seemed to me to be mostly about evolutionary history of the emotions, with little to say about their functions. Finally, I found a book chapter by the psychologist Alan Fridlund, whose title captured my misgivings: “Darwin’s Anti-Darwinism in The Expression of the Emotions in Man and Animals.”35

  Fridlund explained that Darwin wrote his book as a rebuttal to the neurologist and artist Charles Bell (of Bell’s palsy renown in medical circles), who claimed that the thirty-two muscles in the human face had been arranged there by the deity for the purpose of communication.36,37 Darwin countered this thesis by showing remarkable continuities in emotional postures and facial expressions across many species. Darwin so emphasized the continuities that he neglected how emotions have been customized to the needs of a species in a specific situation. He emphasized communication but neglected physiological, cognitive, and motivational functions. In short, Darwin’s book about emotions really is anti-Darwinian. The legacy lives on in continued emphasis on communication via facial expression and relative neglect of questions about exactly how emotions give a selective advantage.

  A second evolutionary approach was proposed in the 1960s by the neuroscientist Paul MacLean. He described what he called the “triune brain,” with three components he viewed as having been added sequentially in the course of evolution.38 The oldest and lowest, the reptilian brain, was said to be the source of instinctual behavior. The middle part, the limbic system, he viewed as the source of emotions. The newest module, the cortex, was said to serve abstraction and to be present only in primates. However, neither the allocation of separate functions to different parts of the brain nor the evolutionary sequence has held up.39 More significant, the theory does not address explicitly how the emotions give selective advantages.

  Modern neuroscientists, such as Joseph LeDoux, use new methods to show how specific sites in the brain, such as the amygdala, contribute to specific emotions, such as fear. His research has found two routes for fear, a fast-reacting “low road” and a slower “high road” that involves more cognitive processing.40 These approaches are much more explicit about the functions of emotions, even if not about how they increase fitness.

  Another evolutionary approach addresses functions explicitly by trying to specify a function for each emotion. One website on mental health says, “The sole function of anger is to stop stress. It does this by discharging or blocking awareness of painful levels of emotional or physical arousal.”41 Another says, “we have recycled the primary function of anger from the protection of life, loved ones, and fellow tribesmen to protection of the ego.”42

  Even some careful scientists say, “each emotion has an inherently adaptive function.”43 The function of sadness is said to be “strengthening social bonds,” “slowing mental
and motor activity” and “communication to the self that there is trouble.”44 Anger “decreases aggression in others, mobilizes energy, and increases blood flow to muscles.”45 “Shame or the anticipation of shame motivates the individual to accept his or her share of responsibility for the welfare of the community.”46

  This approach gets closer to explaining how emotions are useful, and newer work focused on functions is increasingly sophisticated and explicitly evolutionary.47 However, it seems to me that most such approaches misrepresent emotions as if they were components of a designed machine. It is sensible to seek the function of each part in a machine. The crank, the wheel, and the moving rod on the cherry pitter all have specific functions. But emotions were not designed; they evolved. Instead of one function, each emotion has many.

  The big conclusion from my reading project is that attempts to specify functions for each emotion have slowed progress. Emotions make more sense when viewed as special modes of operation that increase ability to cope with certain situations.48 Emotions are analogous to computer programs that adjust many aspects of the organism to efficiently cope with specific situations and tasks.49,50

  What Are Emotions?

  The question has been contentious for centuries. In his lovely textbook about emotions, the psychologist Robert Plutchik listed twenty-one different definitions, culled from hundreds of proposals.51 Every year, new articles and books propose more. At the 2013 Society for Personality and Social Psychology meeting, the session on emotions was titled “What Is an Emotion?” You would think that by now almost everyone would agree on a definition, but different experts emphasize different aspects of emotions, so debates go on and on.

  An evolutionary perspective suggests a simple definition of emotions based on the forces that shaped them: Emotions are specialized states that adjust physiology, cognition, subjective experience, facial expressions, and behavior in ways that increase the ability to meet the adaptive challenges of situations that have recurred over the evolutionary history of a species.52

  Different emotions are like the musical styles programmed into electronic keyboards. Each style sets a combination of instruments, rhythms, chords, and timbre appropriate for a certain kind of music. If the keyboard is set to “classical,” sonorous tones moan with plenty of echo. Set it for “salsa,” and bright horns carry the melody over a lively drumbeat. Set it for “jazz,” and the sound will be a bit different from salsa but very different from classical. Each mode adjusts many aspects to make sounds that are distinctive but that overlap in various ways with others. Just like fear, anger, love, and awe.

  The natural next question is how many emotions exist. Lists of “basic emotions” go back as far as recorded writing. Research in the late twentieth century by Paul Ekman, Carroll Izard, Robert Plutchik, Silvan Tomkins, and others gave the question new legs.53,54,55,56 They asked people to make lists of emotions, and then they looked for those that are common to many lists. Increasingly sophisticated methods and cross-cultural studies confirmed consistent recognition of some emotions, such as fear, joy, sadness, and anger.57,58,59 However, every researcher offers a slightly different list, with the number of basic emotions ranging from three to seventeen.

  Emotions are separate to the extent that they have been differentiated from ancestral emotions to cope with a related but somewhat different situation. This makes arguments about the number of basic emotions unnecessary. Each emotion has a “prototype,” that is, characteristics that describe an exemplar at the center of a cloud of somewhat varying responses.60 Those clouds have overlapping blurry boundaries.

  An imaginary tree illustrates the evolution of the emotions, with interwoven boughs of different but overlapping emotions.61 It is not the nice neat package scientists have been looking for, but it offers an evolutionary framework that can address some important questions. For instance, emotions are either positive or negative because only situations with threats or opportunities influence fitness. Positive emotions encourage organisms to seek out and stay in situations that offer opportunities to do things that are good for their genes. Negative emotions motivate avoidance of and escape from situations that involve threat or loss.

  A Phylogeny of Emotions

  The utility of an emotion depends entirely on the situation. In the face of threats or losses, anxiety and sadness are useful, but happy relaxation is worse than useless. When opportunities emerge, desire and enthusiasm are useful, but worry and sadness are harmful. The advantage goes not to individuals who are constantly anxious, sad, or joyful but to those who experience anxiety when loss is threatened, sadness after a loss, and enthusiasm and joy in the face of opportunity and success.

  If only all situations were so simple. For humans trying to navigate inordinately complex social networks, almost every situation involves conflicting opportunities, risks, gains, and losses, with vast complexity and uncertainty. What do you do when you get an offer of a large grant to pursue your research from a politically tainted source? Or if you find out that a close friend’s spouse is having an affair? Our emotions fuel mental machinations at all hours, especially at night, when we would rather be sleeping.

  People sometimes assume that subjective feeling is the essence of emotion, but feeling is only one aspect. Sometimes it is missing.62,63 I have seen some patients, mostly men, who reported fatigue, weight loss, sleep problems, and lack of initiative but no sadness or hopelessness. They had depression, but I missed the diagnosis repeatedly until I finally realized that subjective experience is only one aspect of depression. Once free from the idea that emotions always involve subjective feelings, it becomes possible to trace the heritage of emotions back to the origins of behavior regulation—all the way back.

  Bacteria don’t have feelings, but they certainly do have different states that turn on when needed.64 The most dramatic shift occurs when their world dries up. A switch flips, and happily swimming bacteria transform into tiny, sturdy spores. Even in stable environments, bacteria demonstrate amazing abilities to adapt to changing circumstances.65 High temperatures induce the synthesis of protective heat shock proteins. Food concentrations higher than they were a half second previously induce counterclockwise rotation of flagellar tails, making them swim straight ahead toward the food. If the concentration declines, the flagella reverse direction, creating a tangle that tumbles the organism in random directions.66 When conditions again look better than they did a half second previously, straight swimming resumes.67,68,69 That is how bacteria navigate to places in your body where they can grow happily.

  A one-second memory and a switch that turns tumbling to forward swimming and back are all it takes for bacteria to swim toward food and away from danger. Doesn’t life feel like that sometimes? You are cruising along, and then suddenly the path ahead looks dark and barren and you find yourself tumbling without a plan or direction. It feels awful, but trying out random directions is better than persisting in efforts that lead nowhere or worse.

  Emotions and Culture

  The labeling, expression, and experience of emotions differ dramatically in different cultures. Even the word emotion has no exact translation in many languages. The closest German word, Gefühl, combines the meanings of emotion and physical sensation. Samoan and French speakers have words that describe “having a feeling” but no word that includes feelings, thoughts, and physical sensations. Germans recognize bittersweet longing as Sehnsucht, but other cultures have no word for such a longing, and lacking the word may make the experience less common. Disgust seems universal, but no Polish word corresponds exactly. Japanese readily recognize amae, a feeling of dependency like what an infant feels toward its mother, but no comparable word exists in English, perhaps because that kind of relationship is less common in the West.

  Culture influences emotions, just as it influences body weight, blood pressure, and most everything else.70 Culture influences what emotions people recognize, the words they use to describe th
em, the kinds of situations that arouse them, and to some extent what emotions are experienced. However, the capacity to feel emotions is a product of natural selection that we share with one another, and to some extent with other species.

  Several scientists have traveled to distant cultures to find out if emotional facial expressions are universal. Psychologist and leading emotion researcher Carroll Izard took thirty-two photographs of faces to eight cultures and found that people everywhere recognized all but a few emotional expressions accurately.71 A German researcher, Irenäus Eibl-Eibesfeldt, got similar results from his extensive studies.72 Another leading emotion expert, Paul Ekman, conducted similar studies that found cross-cultural consistency in the ability to recognize facial expressions of anger, disgust, fear, joy, sadness, and surprise but considerable variation in the ability to recognize expressions of contempt and other emotions.73

  These studies have spurred a generation of controversy, with praise met by criticism,74 rejoinders, and replies to the rejoinders.75 They are swords in debates about nature and nurture. Such controversies make emotion research seem like a jungle of untamed science; however, like the lost medieval cities in Cambodia revealed by ground-penetrating radar, emotions have a consistent structure underneath all the overgrowth.