Analogous experiments have since shown the same effect in many other contexts. In one experiment, the judgment of length was replaced by a judgment of color: volunteers were presented with letters and numbers that varied in hue and asked to judge their “degree of redness.” Those who were given the color samples with the reddest characters grouped together judged those to be more alike in color and more different from the other group than did volunteers who appraised the same samples presented without being grouped.3 In another study, researchers found that if you ask people in a given city to estimate the difference in temperature between June 1 and June 30, they will tend to underestimate it; but if you ask them to estimate the difference in temperature between June 15 and July 15, they will overestimate it.4 The artificial grouping of days into months skews our perception: we see two days within a month as being more similar to each other than equally distant days that occur in two different months, even though the time interval between them is identical.
In all these examples, when we categorize, we polarize. Things that for one arbitrary reason or another are identified as belonging to the same category seem more similar to each other than they really are, while those in different categories seem more different than they really are. The unconscious mind transforms fuzzy differences and subtle nuances into clear-cut distinctions. Its goal is to erase irrelevant detail while maintaining information on what is important. When that’s done successfully, we simplify our environment and make it easier and faster to navigate. When it’s done inappropriately, we distort our perceptions, sometimes with results harmful to others, and even ourselves. That’s especially true when our tendency to categorize affects our view of other humans—when we view the doctors in a given practice, the attorneys in a given law firm, the fans of a certain sports team, or the people in a given race or ethnic group as more alike than they really are.
A CALIFORNIA ATTORNEY wrote about the case of a young Salvadoran man who had been the only nonwhite employee at a box-manufacturing plant in a rural area. He had been denied a promotion, then fired for habitual tardiness and for being “too easy-going.” The man claimed that the same could be said of others but that their tardiness went unnoticed. With them, he said, the employer seemed to understand that sometimes a sickness in the family, a problem with a child, or trouble with the car can lead to being late. But with him, lateness was automatically attributed to laziness. His shortcomings were amplified, he said, and his achievements went unrecognized. We’ll never know whether his employer really overlooked the Salvadoran man’s individual traits, whether his employer lumped him in the general category “Hispanic” and then interpreted his behavior in terms of a stereotype. The employer certainly disputed that accusation. And then he added, “Mateo’s being a Mexican didn’t make any difference to me. It’s like I didn’t even notice.”5
The term “stereotype” was coined in 1794 by the French printer Firmin Didot.6 It referred to a type of printing process by which cookie-cutter-like molds could be used to produce duplicate metal plates of hand-set type. With these duplicate plates, newspapers and books could be printed on several presses at once, enabling mass production. The term was first used in its current sense by the American journalist and intellectual Walter Lippmann in his 1922 book Public Opinion, a critical analysis of modern democracy and the role of the public in determining its course. Lippmann was concerned with the ever-growing complexity of the issues facing the voters and the manner in which they developed their views on those issues. He was particularly worried about the role of the mass media. Employing language that sounds as if it was pulled from a recent scholarly article on the psychology of categories, Lippmann wrote, “The real environment is altogether too big, too complex, and too fleeting for direct acquaintance…. And although we have to act in that environment, we have to reconstruct it on a simpler model before we can manage with it.”7 That simpler model was what he called the stereotype.
Lippmann recognized that the stereotypes people use come from cultural exposure. His was an era in which mass-circulation newspapers and magazines, as well as the new medium of film, were distributing ideas and information to audiences larger and more far-flung than had ever before been possible. They made available to the public an unprecedentedly wide array of experiences of the world, yet without necessarily providing an accurate picture. The movies, in particular, conveyed a vivid, real-looking portrait of life, but one often peopled by stock caricatures. In fact, in the early days of film, filmmakers combed the streets looking for “character actors,” easily identifiable social types, to play in their movies. As Lippmann’s contemporary Hugo Münsterberg wrote, “If the [producer] needs the fat bartender with his smug smile, or the humble Jewish peddler, or the Italian organ grinder, he does not rely on wigs and paint; he finds them all ready-made on the East Side [of New York].” Stock character types were (and still are) a convenient shorthand—we recognize them at once—but their use amplifies and exaggerates the character traits associated with the categories they represent. According to the historians Elizabeth Ewen and Stuart Ewen, by noting the analogy between social perception and a printing process capable of generating an unlimited number of identical impressions, “Lippmann had identified and named one of the most potent features of modernity.”8
Though categorizations due to race, religion, gender, and nationality get the most press, we categorize people in many other ways as well. We can probably all think of cases in which we lumped athletes with athletes, or bankers with bankers, in which we and others have categorized people we’ve met according to their profession, appearance, ethnicity, education, age, or hair color or even by the cars they drive. Some scholars in the sixteenth and seventeenth centuries even categorized people according to the animal they best resembled, as pictured on the facing page, in images from De Humana Physiognomonia, a kind of field guide to human character written in 1586 by the Italian Giambattista della Porta.9
A more modern illustration of categorization by appearance played out early one afternoon in an aisle of a large discount department store in Iowa City. There, an unshaven man in soiled, patched blue jeans and a blue workman’s shirt shoved a small article of clothing into the pocket of his jacket. A customer down the aisle looked on. A little later, a well-groomed man in pressed dress slacks, a sports jacket, and a tie did the same, observed by a different customer who happened to be shopping nearby. Similar incidents occurred again and again that day, well into the evening, over fifty more times, and there were a hundred more such episodes at other nearby stores. It was as if a brigade of shoplifters had been dispatched to rid the town of cheap socks and tacky ties. But the occasion wasn’t National Kleptomaniacs’ Day; it was an experiment by two social psychologists.10 With the full cooperation of the stores involved, the researchers’ aim was to study how the reactions of bystanders would be affected by the social category of the offender.
The shoplifters were all accomplices of the researchers. Immediately after each shoplifting episode, the thief walked out of hearing distance of the customer but remained within eyesight. Then another research accomplice, dressed as a store employee, stepped to the vicinity of the customer and began rearranging merchandise on the shelves. This gave the customer an easy opportunity to report the crime. The customers all observed the identical behavior, but they did not all react to it in the same way. Significantly fewer of the customers who saw the well-dressed man commit the crime reported it, as compared to those who had watched the scruffy individual. Even more interesting were the differences in attitude the customers had when they did alert the employee to the crime. Their analysis of events went beyond the acts they had observed—they seemed to form a mental picture of the thief based as much on his social category as on his actions. They were often hesitant when reporting the well-dressed criminal but enthusiastic when informing on the unkempt perpetrator, spicing up their accounts with utterances along the lines of “that son of a bitch just stuffed something down his coat.” It was as if the unkempt man’s appearance was a signal to the customers that shoplifting must be the least of his sins, an indicator of an inner nature as soiled as his clothes.