The Search for Emotion’s “Fingerprints”
Once upon a time, in the 1980s, I thought I would be a clinical psychologist. I headed into a Ph.D. program at the University of Waterloo, expecting to learn the tools of the trade as a psychotherapist and one day treat patients in a stylish yet tasteful office. I was going to be a consumer of science, not a producer. I certainly had no intention of joining a revolution to unseat basic beliefs about the mind that have existed since the days of Plato. But life sometimes tosses little surprises in your direction.
It was in graduate school that I felt my first tug of doubt about the classical view of emotion. At the time, I was researching the roots of low self-esteem and how it leads to anxiety or depression. Numerous experiments showed that people feel depressed when they fail to live up to their own ideals, but when they fall short of a standard set by others, they feel anxious. My first experiment in grad school was simply to replicate this well-known phenomenon before building on it to test my own hypotheses. In the course of this experiment, I asked a large number of volunteers if they felt anxious or depressed using well-established checklists of symptoms.1
I’d done more complicated experiments as an undergraduate student, so this one should have been a piece of cake. Instead, it crashed and burned. My volunteers did not report anxious or depressed feelings in the expected pattern. So I tried to replicate a second published experiment, and it failed too. I tried again, over and over, each experiment taking months. After three years, all I’d achieved was the same failure eight times in a row. In science, experiments often don’t replicate, but eight consecutive failures is an impressive record. My internal critic taunted me: not everyone is cut out to be a scientist.
When I looked closely at all the evidence I had collected, however, I noticed something consistently odd across all eight experiments. Many of my subjects appeared to be unwilling, or unable, to distinguish between feeling anxious and feeling depressed. Instead, they had indicated feeling both or neither; rarely did a subject report feeling just one. This made no sense. Everybody knows that anxiety and depression, when measured as emotions, are decidedly different. When you’re anxious, you feel worked up, jittery, like you’re worried something bad will happen. In depression you feel miserable and sluggish; everything seems horrible and life is a struggle. These emotions should leave your body in completely opposite physical states, and so they should feel different and be trivial for any healthy person to tell apart. Nevertheless, the data declared that my test subjects weren’t doing so. The question was .?.?. why?
As it turned out, my experiments weren’t failing after all. My first “botched” experiment actually revealed a genuine discovery ?— ?that people often did not distinguish between feeling anxious and feeling depressed. My next seven experiments hadn’t failed either; they’d replicated the first one. I also began noticing the same effect lurking in other scientists’ data. After completing my Ph.D. and becoming a university professor, I continued pursuing this mystery. I directed a lab that asked hundreds of test subjects to keep track of their emotional experiences for weeks or months as they went about their lives. My students and I inquired about a wide variety of emotional experiences, not just anxious and depressed feelings, to see if the discovery generalized.
These new experiments revealed something that had never been documented before: everyone we tested used the same emotion words like “angry,” “sad,” and “afraid” to communicate their feelings but not necessarily to mean the same thing. Some test subjects made fine distinctions with their word use: for example, they experienced sadness and fear as qualitatively different. Other subjects, however, lumped together words like “sad” and “afraid” and “anxious” and “depressed” to mean “I feel crappy” (or, more scientifically, “I feel unpleasant”). The effect was the same for pleasant emotions like happiness, calmness, and pride. After testing over seven hundred American subjects, we discovered that people vary tremendously in how they differentiate their emotional experiences.
A skilled interior designer can look at five shades of blue and distinguish azure, cobalt, ultramarine, royal blue, and cyan. My husband, on the other hand, would call them all blue. My students and I had discovered a similar phenomenon for emotions, which I described as emotional granularity.2
Here’s where the classical view of emotion entered the picture. Emotional granularity, in terms of this view, must be about accurately reading your internal emotional states. Someone who distinguished among different feelings using words like “joy,” “sadness,” “fear,” “disgust,” “excitement,” and “awe” must be detecting physical cues or reactions for each emotion and interpreting them correctly. A person exhibiting lower emotional granularity, who uses words like “anxious” and “depressed” interchangeably, must be failing to detect these cues.
I began wondering if I could teach people to improve their emotional granularity by coaching them to recognize their emotional states accurately. The key word here is “accurately.” How can a scientist tell if someone who says “I’m happy” or “I’m anxious” is accurate? Clearly, I needed some way to measure an emotion objectively and then compare it to what the person reports. If a person reports feeling anxious, and the objective criteria indicate that he is in a state of anxiety, then he is accurately detecting his own emotion. On the other hand, if the objective criteria indicate that he is depressed or angry or enthusiastic, then he’s inaccurate. With an objective test in hand, the rest would be simple. I could ask a person how she feels and compare her answer to her “real” emotional state. I could correct any of her apparent mistakes by teaching her to better recognize the cues that distinguish one emotion from another and improve her emotional granularity.
Like most students of psychology, I had read that each emotion is supposed to have a distinct pattern of physical changes, roughly like a fingerprint. Each time you grasp a doorknob, the fingerprints that you leave behind may vary depending on the firmness of your grip, how slippery the surface is, or how warm and pliable your skin is at that moment. Nevertheless, your fingerprints look similar enough each time to identify you uniquely. The “fingerprint” of an emotion is likewise assumed to be similar enough from one instance to the next, and in one person to the next, regardless of age, sex, personality, or culture. In a laboratory, scientists should be able to tell whether someone is sad or happy or anxious just by looking at physical measurements of a person’s face, body, and brain.
I felt confident that these emotion fingerprints could provide the objective criteria I needed to measure emotion. If the scientific literature was correct, then assessing people’s emotional accuracy would be a breeze. But things did not turn out quite as I expe...