People are often very skilled at person perception—the process of learning about other people—and our brains are designed to help us judge others efficiently (Haselton & Funder, 2006; Macrae & Quadflieg, 2010). Infants prefer to look at faces of people more than they do other visual patterns, and children quickly learn to identify people and their emotional expressions (Turati, Cassia, Simion, & Leo, 2006). As adults, we are able to identify and remember a potentially unlimited number of people as we navigate our social environments (Haxby, Hoffman, & Gobbini, 2000), and we form impressions of those others quickly and without much effort (Carlston & Skowronski, 2005; Fletcher-Watson, Findlay, Leekam, & Benson, 2008). Furthermore, our first impressions are, at least in some cases, remarkably accurate (Ambady, Bernieri, & Richeson, 2000).

Recent research is beginning to uncover the areas in our brain where person perception occurs. In one relevant study, Mason and Macrae (2004) used functional magnetic resonance imaging (fMRI) scans to test whether people stored information about other people in a different location in the brain than where they stored information about animals, and they found that this was the case. Specific areas of the prefrontal cortex were found to be more active when people made judgments about people rather than dogs (Figure 5.2).

Learning about people is a lot like learning about any other object in our environment, with one major exception. With an object, there is no interaction: we learn about the characteristics of a car or a cell phone, for example, without any concern that the car or the phone is learning about us. It is a one-way process. With people, in contrast, there is a two-way social process: just as we are learning about another person, that person is learning about us, or potentially attempting to keep us from accurately perceiving him or her. For instance, research has found that when other people are looking directly at us, we process their features more fully and faster, and we remember them better than when the same people are not looking at us (Hood & Macrae, 2007).

In the social dynamic with others, then, we have two goals: first, we need to learn about them, and second, we want them to learn about us (and, we hope, like and respect us). Our focus here is on the former process—how we make sense of other people. But remember that just as you are judging them, they are judging you.

We have seen in the chapter, “The Self”,  that when people are asked to describe themselves, they generally do so in terms of their physical features (“I am really tall”), social category memberships (“I am a woman”), and traits (“I am friendly”). These characteristics well reflect the dimensions we use when we try to form impressions of others. In this section, we will review how we initially use the physical features and social category memberships of others (e.g., male or female, race, and ethnicity) to form judgments and then will focus on the role of personality traits in person perception.

Nonverbal Behavior

One way that the participants in the studies described above may have been able to form such accurate impressions of instructors on the basis of such little information was by viewing their nonverbal behavior. Nonverbal behavior is any type of communication that does not involve speaking, including facial expressions, body language, touching, voice patterns, and interpersonal distance. Nonverbal behaviors are used to reinforce spoken words (Hostetter, 2011) but also include such things as interpersonal distance (how far away from you the other person stands), tone of voice, eye gaze, and hand gestures and body positions (DePaulo et al., 2003).

The ability to decode nonverbal behavior is learned early, even before the development of language (Walker-Andrews, 2008). We tend to like people who have a pleasant tone of voice and open posture, who stand an appropriate distance away from us, and who look at and touch us for the “right” amount of time—not too much or too little. And, of course, behavior matters; people who walk faster are perceived as happier and more powerful than those who walk more slowly (Montepare & Zebrowitz-McArthur, 1988). (For more insight into the relationship between nonverbal communication and success, see social psychologist Amy Cuddy’s fascinating TED Talk here: http://www.ted.com/talks/amy_cuddy_your_body_language_shapes_who_you_are).

The importance of body movement has been demonstrated in studies in which people are viewed in point-light displays in dark rooms with only small lights at their joints. Research has found that observers are able to accurately recognize the behavior of others from these minimal displays (Clarke, Bradshaw, Field, Hampson, & Rose, 2005; Johnson, Gill, Reichman, & Tassinary, 2007; Heberlein, Adolphs, Tranel, & Damasio, 2004; Figure 5.4 “Point-Light Displays”). People can also determine personality by tone of voice provided by degraded and incomprehensible speech (Ambady, Krabbenhoft, & Hogan, 2006).

People can accurately detect behaviors, emotions, and traits from point-light displays. You might want to try your skills here: http://astro.temple.edu/~tshipley/mocap/dotMovie.html.

Although they may be pretty good at it in some cases, people are often not aware of their ability to make accurate judgments. Rule, Ambady, Adams, and Macrae (2008) found that even though the participants in their research were quite accurate in their perceptions, they could not articulate how they made their judgments. They claimed that they were “just guessing” and could hardly believe that they were getting the judgments right. These results suggest that they were made without any conscious awareness on the part of the judgers. Furthermore, the participants’ judgments of their own accuracy were not generally correlated with their actual accurate judgments.

The particular nonverbal behaviors that we use, as well as their meanings, are determined by social norms, and these norms may vary across cultures. For example, people who live in warm climates nearer the equator use more nonverbal communication (e.g., talking with their hands or showing strong facial expressions) and are more likely to touch each other during conversations than people who live in colder climates nearer Earth’s poles (Manstead, 1991; Pennebaker, Rime, & Blankenship, 1996). And the appropriate amount of personal space to keep between ourselves and others also varies across cultures. In some cultures—for instance, those of South American countries—it is appropriate to stand very close to another person while talking to him or her; in other cultures—for example, in the United States and Western Europe—more interpersonal space is the norm (Knapp & Hall, 2006). The appropriate amount of eye contact with others is also determined by culture. In Latin America, it is appropriate to lock eyes with another person, whereas in Japan, people more often try to avoid eye contact.

Although nonverbal behaviors can be informative during the initial stages of person perception, they are limited in what they can convey. In general, they communicate our own status or dominance (self-concern) as well as our interest in or liking of another (other-concern). If we notice that someone is smiling and making eye contact with us while leaning toward us in conversation, we can be pretty sure that he or she likes us. On the other hand, if someone frowns at us, touches us inappropriately, or moves away when we get close, we may naturally conclude that he or she does not like us.

We may also use nonverbal behaviors to try out new situations: If we move a little closer and look at someone a bit longer, we communicate our interest. If these responses are reciprocated by the other person, that can indicate that he or she likes us, and we can move on to share other types of information. If the initial nonverbal behaviors are not reciprocated, then we may conclude that the relationship may not work out and we can withdraw before we go “too far.”

Nonverbal behavior provides different information than verbal behavior because people frequently say one thing and do another. Perhaps you remember being really angry at someone but not wanting to let on that you were mad, so you tried to hide your emotions by not saying anything. But perhaps your nonverbal behavior eventually gave you away to the other person: although you were trying as hard as you could not to, you just looked angry. We frequently rely more on nonverbal than on verbal behavior when messages are contradictory. One reason for this is that we know that it is relatively easy to monitor our verbal behavior but harder to control the nonverbal. However, we expect that people who need to deceive others—for instance, good poker players—are able to monitor their nonverbal behavior better than most people, making it difficult to get a good read on them.

Because we use nonverbal behaviors so frequently in our social interactions, we are fluent readers of them. We also realize that we can better communicate with others when we use them. Indeed, it is difficult to communicate accurately when we cannot express ourselves nonverbally (Krauss, Chen, & Chawla, 1996). You probably have noticed this yourself. If you e-mail or text a message to your friend, for instance, you need to be careful about using sarcasm because he or she might misinterpret your meaning. Because nonverbal information is so important, we quickly learned to incorporate it, in the form of emoticons, in our text messages (Figure 5.6 ).

Detecting Danger by Focusing on Negative Information

You may have noticed when you first looked at the images presented earlier in this chapter that you tended to like some of the people and to dislike others. It is not surprising that you had these emotions—these initial affective reactions are an essential and highly adaptive part of person perception. One of the things that we need to determine when we first perceive someone is whether that person poses any threat to our well-being. We may dislike or experience negative emotions about people because we feel that they are likely to harm us, just as we may like and feel positively about them if we feel that they can help us (Rozin & Royzman, 2001). Research has found that the threat and the trustworthiness of others are particularly quickly perceived, at least by people who are not trying to hide their intentions (Bar, Neta, & Linz, 2006; Todorov, Said, Engel, & Oosterhof, 2008).

Most people with whom we interact are not dangerous, nor do they create problems for us. In fact, when we are asked to rate how much we like complete strangers, we generally rate them positively (Sears, 1986). Because we generally expect people to be positive, people who are negative or threatening are salient, likely to create strong emotional responses, and relatively easy to spot.

Compared with positive information, negative information about a person tends to elicit more physiological arousal, draw greater attention, and exert greater impact on our judgments and impressions of the person. Hansen and Hansen (1988) had undergraduate students complete a series of trials in which they were shown, for very brief time periods, “crowds” of nine faces (Figure 5.7, “Faces”). On some of the trials, all the faces were happy or all the faces were angry. On other trials, the “crowd” was made up of eight happy faces and one angry face, or eight angry faces and one happy face. For each trial, the participants were instructed to say, as quickly as possible, whether the crowd contained a discrepant face or not. Hansen and Hansen found that the students were significantly faster at identifying the single angry face among the eight happy ones than they were at identifying the single happy face among the eight angry ones. They also made significantly fewer errors doing so. The researchers’ conclusion was that angry, and thus threatening, faces quickly popped out from the crowd. Similarly, Ackerman and colleagues (2006) found that people were better at recognizing the faces of other people when those faces had angry, rather than neutral, expressions, and Dijksterhuis and Aarts (2003) found that people could more quickly and more accurately recognize negative, rather than positive, words.

Because negative faces are more salient and therefore more likely to grab our attention than are positive faces, people are faster at locating a single negative face in a display of positive faces than they are to locate a single positive face in a display of negative faces.

Our brains seem to be hardwired to detect negative behaviors (Adams, Gordon, Baird, Ambady, & Kleck, 2003), and at an evolutionary level this makes sense. It is important to tell the “good guys” from the “bad guys” and to try to avoid interacting with the latter. In one study, Tiffany Ito and her colleagues (Ito, Larsen, Smith, & Cacioppo, 1998) showed college students a series of positive, negative, and neutral images while their event-related brain potentials were collected. The researchers found that different parts of the brain reacted to positive and negative images and that the response to negative images was greater overall. They concluded that “negative information weighs more heavily on the brain” (p. 887). In sum, the results of research in person perception are clear: when we are perceiving people, negative information is simply more influential than positive information (Pratto & John, 1991).

Social Psychology in the Public Interest

Detecting Deception

One important person perception task that we must all engage in sometimes is to try to determine whether other people are lying to us. We might wonder whether our poker opponent is bluffing, whether our partner is being honest when she tells us she loves us, or whether our boss is really planning to give us the promotion he has promised. This task is particularly important for members of courtroom juries, who are asked determine the truth or falsehood of the testimony given by witnesses. And detecting deception is perhaps even more important for those whose job is to provide public security. How good are professionals, such as airport security officers and police detectives at determining whether or not someone is telling the truth?

It turns out that the average person is only moderately good at detecting deception and that experts do not seem to be much better. In a recent meta-analysis, researchers looked at over 200 studies that had tested the ability of almost 25,000 people to detect deception (Bond & DePaulo, 2006). The researchers found that people were better than chance at doing so but were not really that great. The participants in the studies were able to correctly identify lies and truths about 54% of the time (chance performance is 50%). This is not a big advantage, but it is one that could have at least some practical consequences and that suggests that we can at least detect some deception. However, the meta-analysis also found that experts—including police officers, detectives, judges, interrogators, criminals, customs officials, mental health professionals, polygraph examiners, job interviewers, federal agents, and auditors—were not significantly better at detecting deception than were nonexperts.

Why is it so difficult for us to detect liars? One reason is that people do not expect to be lied to. Most people are good and honest folk, and we expect them to tell the truth, and we tend to give them the benefit of the doubt (Buller, Stiff, & Burgoon, 1996; Gilbert, Krull, & Malone, 1990). In fact, people are more likely to expect deception when they view someone on a videotape than when they are having an interpersonal interaction with the person. It’s as if we expect the people who are right around us to be truthful (Bond & DePaulo, 2006).

A second reason is that most people are pretty good liars. The cues that liars give off are quite faint, particularly when the lies that they are telling are not all that important. Bella DePaulo and her colleagues (DePaulo et al., 2003) found that in most cases it was very difficult to tell if someone was lying, although it was easier when the liar was trying to cover up something important (e.g., a sexual transgression) than when he or she was lying about something less important. De Paulo and colleagues did find, however, that there were some reliable cues to deception.

Compared with truth tellers, liars:

• Made more negative statements overall
• Appeared more tense
• Provided fewer details in their stories
• Gave accounts that were more indirect and less personal
• Took longer to respond to questions and exhibited more silent pauses when they were not able to prepare their responses
• Gave responses that were briefer and spoken in a higher pitch

A third reason it is difficult for us to detect liars is that we tend to think we are better at catching lies than we actually are. This overconfidence may prevent us from working as hard as we should to try to uncover the truth.

Finally, most of us do not really have a very good idea of how to detect deception; we tend to pay attention to the wrong things. Many people think that a person who is lying will avert his or her gaze or will not smile or that perhaps he or she will smile too much. But it turns out that faces are not that revealing. The problem is that liars can more easily control their facial expressions than they can control other parts of their bodies. In fact, Ekman and Friesen (1974) found that people were better able to detect other people’s true emotions when they could see their bodies but not their faces than when they could see their faces but not their bodies. Although we may think that deceivers do not smile when they are lying, it is actually common for them to mask their statements with false smiles—smiles that look very similar to the more natural smile that we make when we are really happy (Ekman & Davidson, 1993; Frank & Ekman, 1993).

Recently, advances in technology have begun to provide new ways to assess deception. Some software analyzes the language of truth tellers, other software analyzes facial microexpressions that are linked with lying (Newman, Pennebaker, Berry, & Richards, 2003), and still other software uses neuroimaging techniques to try to catch liars (Langleben et al., 2005). Whether these techniques will be successful, however, remains to be seen.

Judging People by Their Traits

Although we can learn some things about others by observing their physical characteristics and their nonverbal behaviors, to really understand them we will eventually need to know their personality traits. Traits are important because they are the basic language by which we understand and communicate about people. When we talk about other people, we describe their traits. Our friends are “fun,” “creative,” and “crazy in a good way,” or “quiet,” “serious,” and “controlling.” The language of traits is a powerful one—indeed, there are over 18,000 trait terms in the English language.

Combining Traits: Information Integration

Let’s consider for a moment how people might use trait terms to form an overall evaluation of another person. Imagine that you have to describe two friends of yours, Amir and Connor, to another person, Rianna, who might be interested in dating one of them. You’ll probably describe the two men in terms of their physical features first, but then you’ll want to say something about their personalities. Let’s say that you want to make both Amir and Connor sound as good as possible to Rianna, but you also want to be honest and not influence her one way or the other. How would you do that? You would probably start by mentioning their positive traits: Amir is “intelligent” and “serious”; Connor is “fun” and “exciting.” But to be fair, you would also need to mention their negative traits: Amir sometimes seems “depressed,” and Connor can be “inconsiderate.”

You might figure that Rianna will just combine whatever information you give her, perhaps in a mathematical way. For instance, she might listen to all the traits that you mention, decide how positive or negative each one is, and then add the traits together or average them. Research has found that people do exactly that, both for strangers and for people whom they know very well (Anderson, 1974; Falconi & Mullet, 2003). Consider what might happen if you gave Rianna the following information:

• Amir is smart, serious, kind, and sad.
• Connor is fun, happy, selfish, and inconsiderate.

Rianna might decide to score each trait on a scale of +5 (very positive) to –5 (very negative). Once she has these numbers, she could then either add them together or average them to get an overall judgment.

Amir
Smart	+5
Serious	+1
Kind	+4
Sad	–4
Sum	+6.0
Average	+1.5
Connor
Fun	+3
Happy	+2
Selfish	–4
Inconsiderate	–5
Sum	–4.0
Average	–1.0

Based on this scoring, Rianna would probably decide that she likes Amir more than Connor. Of course, different people might weight the traits in somewhat different ways, and this would lead different people to draw different impressions about Amir and Connor. But there is pretty good agreement among most people about the meaning of traits, at least in terms of the overall positivity or negativity of each trait, and thus most people would be likely to draw similar conclusions.

Now imagine that you later thought of some other new, moderately positive characteristics about Amir—that he was also “careful” and “helpful.” Whether you told Rianna about them might depend on how you thought they would affect her overall impression of Amir. Perhaps these new traits would make Rianna like Amir more (after all, they do add new positive information about him). But perhaps they might make her like him less (if the new, moderately positive information diluted the existing positive impression she has already formed about him).

One way to think about this is to consider whether Rianna might be adding the traits together or averaging them. In our first example, it didn’t matter because the outcome was the same. But now it might—if she’s adding the traits together, then Rianna will probably like Amir more after she hears the new information, because new positive traits have been added to the existing sum score. If she is averaging the traits together, however, then Rianna will probably like him less than she did before, because the new, more moderate information tends to dilute the initial impressions.

It turns out that in most cases, our judgments are better predicted by mental averaging than by mental adding (Mills, 2007). What this means is that when you are telling someone about another person and you are trying to get him or her to like the person, you should say the most positive things that you know but leave out the more moderate (although also positive) information. The moderate information is more likely to dilute, rather than enhance, the more extreme information.

The Importance of the Central Traits Warm and Cold

Although the averaging model is quite good at predicting final impressions, it is not perfect. This is because some traits are simply weighted more heavily than others. For one, negative information is more heavily weighted than is positive information (Rozin & Royzman, 2001). In addition to the heavy weight that we give to negative traits, we give a particular emphasis to the traits “warm” and “cold.” Imagine two men, Brad and Phil, who were described with these two sets of characteristics:

• Brad is industrious, critical, warm, practical, and determined.
• Phil is industrious, critical, cold, practical, and determined.

As you can see, the descriptions are identical except for the presence of “warm” and “cold.” In a classic study, Solomon Asch (1946) found that people described with these two sets of traits were perceived very differently—the “warm” person very positively and the “cold” person very negatively.

To test whether or not these differences would influence real behavior, Harold Kelley (1950) had students read about a professor who was described either as “rather cold” or as “very warm.” Then the professor came into the classroom and led a 20-minute discussion group with the students. Although the professor behaved in the same way for both groups, the students nevertheless reacted very differently to him. The students who were expecting the “warm” instructor were more likely to participate in the discussion, in comparison with those who were expecting him to be “cold.” And at the end of the discussion, the students also rated the professor who had been described as “warm” as being significantly more humorous, sociable, popular, and better natured than the “cold” professor. Moreover, the effects of warmth and coolness seem to be wired into our bodily responses. Research has found that even holding a cup of hot versus iced coffee, or making judgments in warm versus cold rooms leads people to judge others more positively (Ijzerman & Semin, 2009; Williams & Bargh, 2008).

In short, the particular dimension warm versus cold makes a big difference in how we perceive people—much bigger than do other traits. As a result, the traits of warm and cold are known as central traits, which are characteristics that have a very strong influence on our impressions of others (Asch, 1946). The powerful influence of central traits is due to two things. One, they lead us to make inferences about other traits that might not have been mentioned. The students who heard that the professor was “warm” might also have assumed that he had other positive traits (maybe “nice” and “funny”), in comparison with those who heard that he was “cold.” Two, the important central traits also color our perceptions of the other traits that surround them. When a person is described as “warm” and “intelligent,” the meaning of “intelligent” seems a lot better than does the term “intelligent” in the context of a person who is also “cold.” Overall, the message is clear: if you want to get someone to like you, try to act in a warm manner toward them. Be friendly, nice, and interested in what they say. This attention you pay to the other will be more powerful than any other characteristics that you might try to display to them. The importance of perceptions of warmth-coldness has been confirmed in many other contexts. For example, in the field of psychotherapy, many studies have indicated that therapists’ warmth, empathy, and genuineness are the three most important traits in establishing a strong and trusting relationship with clients, which in turn leads to positive change (Shapiro, 1969).

First Impressions Matter: The Primacy Effect

It has frequently been said that “first impressions matter.” Social psychological research supports this idea. The primacy effect describes the tendency for information that we learn first to be weighted more heavily than is information that we learn later. One demonstration of the primacy effect was conducted by Solomon Asch (1946). In his research, participants learned some traits about a person and then made judgments about him. One half of the participants saw this list of traits:

• Intelligent, industrious, impulsive, critical, stubborn, envious

The other half of the participants saw this list:

• Envious, stubborn, critical, impulsive, industrious, intelligent

You may have noticed something interesting about these two lists—they contain exactly the same traits but in reverse order.

Asch discovered something interesting in his study: because the traits were the same, we might have expected that both groups would form the same impression of the person, but this was not at all the case. Rather, Asch found that the participants who heard the first list, in which the positive traits came first, formed much more favorable impressions than did those who heard the second list, in which the negative traits came first. Similar findings were found by Edward Jones (1968), who had participants watch one of two videotapes of a woman taking an intelligence test. In each video, the woman correctly answered the same number of questions and got the same number wrong. However, when the woman got most of her correct answers in the beginning of the test but got more wrong near the end, she was seen as more intelligent than when she got the same number correct but got more correct at the end of the test.

Primacy effects also show up in other domains, even in those that seem really important. For instance, Koppell and Steen (2004) found that in elections in New York City, the candidate who was listed first on the ballot was elected more than 70% of the time, and Miller and Krosnick (1998) found similar effects for candidate preferences in laboratory studies.

This is not to say that it is always good to be first. In some cases, the information that comes last can be most influential. Recency effects, in which information that comes later is given more weight, although much less common than primacy effects, may sometimes occur. For example, de Bruin (2005) found that in competitions such as the Eurovision Song Contest and ice skating, higher marks were given to competitors who performed last.

Considering the primacy effect in terms of the cognitive processes central to human information processing leads us to understand why it can be so powerful. One reason is that humans are cognitive misers. Because we desire to conserve our energy, we are more likely to pay more attention to the information that comes first and less likely to attend to information that comes later. In fact, when people read a series of statements about a person, the amount of time they spend reading the items declines with each new piece of information (Belmore & Hubbard, 1987). Not surprisingly, then, we are more likely to show the primacy effect when we are tired than when we are wide awake and when we are distracted than when we are paying attention (Webster, Richter, & Kruglanski, 1996).

Another reason for the primacy effect is that the early traits lead us to form an initial expectancy about the person, and once that expectancy is formed, we tend to process information in ways that keep that expectancy intact. Thinking back to Chapter 2 and the discussion of social cognition, we can see that this of course is a classic case of assimilation—once we have developed a schema, it becomes difficult to change it. If we learn that a person is “intelligent” and “industrious,” those traits become cognitively accessible, which leads us to develop a positive expectancy about the person. When the information about the negative features comes later, these negatives will be assimilated into the existing knowledge more than the existing knowledge is accommodated to fit the new information. Once we have formed a positive impression, the new negative information just doesn’t seem as bad as it might have been had we learned it first. This is an important factor in explaining the halo effect, which is the influence of a global positive evaluation of a person on perceptions of their specific traits. Put simply, if we get an initially positive general impression of someone, we often see their specific traits more positively. The halo effect has been demonstrated in many social contexts, including a classic investigation by Bingham and Moore (1931) on job interviewing and a far more recent study of students’ evaluations of their professors (Keeley, English, Irons, & Hensley, 2013).

You can be sure that it would be good to take advantage of the primacy and halo effects if you are trying to get someone you just met to like you. Begin with your positive characteristics, and only bring the negatives up later. This will create a much better outcome than beginning with the negatives.