(Measures) Behavioral Measures
One alternative to self-report is to measure behavior. Although the measures shown in Table 4.1 are rather straightforward, social scientists have used a surprising variety of behavioral measures to help them assess the conceptual variables of interest. Table 4.5 represents some that you might fi nd interesting that were sent to me by my social psychology colleagues. Indeed, the types of behaviors that can be measured are limited only by the creativity of the researchers. Some of the types of behavioral variables that form the basis of measured variables in behavioral science include those based on:
Frequency (for instance, frequency of stuttering as a measure of anxiety in interpersonal relations)
Duration (for instance, the number of minutes working at a task as a measure of task interest)
Intensity (for instance, how hard a person claps his or her hands as a measure of effort)
Latency (for instance, the number of days before a person begins to work on a project as a measure of procrastination)
Speed (for instance, how long it takes a mouse to complete a maze as a measure of learning)
Although some behaviors, such as how close a person sits to another person, are relatively easy to measure, many behavioral measures are diffi cult to operationally defi ne and effectively code. For instance, you can imagine that it would be no easy task to develop a behavioral measure of “aggressive play” in children. In terms of the operational defi nition, decisions would have to be made about whether to include verbal aggression, whether some types of physical aggression (throwing stones) should be weighted more heavily than other types of physical aggression (pushing), and so forth. Then the behaviors would have to be coded. In most cases, complete coding systems are worked out in advance, and more than one experimenter makes ratings of the behaviors, thereby allowing agreement between the raters to be assessed. In somecases, videotapes may be made so that the behaviors can be coded at a later time. We will discuss techniques of coding behavioral measures more fully in Chapter 7.
Nonreactive Measures
Behavioral measures have a potential advantage over self-report measures— because they do not involve direct questioning of people, they are frequently less reactive. This is particularly true when the research participant (1) is not aware that the measurement is occurring, (2) does not realize what the measure is designed to assess, or (3) cannot change his or her responses, even if he or she desires to.
Nonreactive Behavioral Measures. are frequently used to assess attitudes that are unlikely to be directly expressed on self-report measures, such as racial prejudice. For instance, Word, Zanna, and Cooper (1974) coded the nonverbal behavior of White male participants as they conducted an interview with another person, who was either Black or White. The researchers found that the interviewers sat farther away from the Black interviewees than from the White interviewees, made more speech errors when talking to the Blacks, and terminated the interviews with the Blacks sooner than with the Whites. This experiment provided insights into the operation of prejudice that could not have been obtained directly because, until the participants were debriefed, they did not know that their behavior was being measured or what the experiment was about.
Some behavioral measures reduce reactivity because they are so indirect that the participants do not know what the measure is designed to assess. For instance, some researchers studying the development of impressions of others will provide participants with a list of behaviors describing another person and then later ask them to remember this information or to make decisions about it. Although the participants think that they are engaging in a memory test, what they remember about the behaviors and the speed with which they make decisions about the person can be used to draw inferences about whether the participants like or dislike the other person and whether they use stereotypes in processing the information. The use of nonreactive behavioral measures is discussed in more detail in a book by Webb, Campbell, Schwartz, Sechrest, and Grove (1981).
Psychophysiological Measures
In still other cases, behavioral measures reduce reactivity because the individual cannot directly control his or her response. One example is the use of psychophysiological measures, which are designed to assess the physiological functioning of the body’s nervous and endocrine systems (Cacioppo, Tassinary, & Berntson, 2000).
Some psychophysiological measures are designed to assess brain activity, with the goal of determining which parts of the brain are involved in which types of information processing and motor activities. These brain measures include the electroencephalogram (EEG), magnetic resonance imaging (MRI), positron-emission tomography (PET), and computerized axial tomography (CAT). In one study using these techniques, Harmon-Jones and Sigelman (2001) used an EEG measure to assess brain activity after research participants had been insulted by another person. Supporting their hypotheses, they found that electrical brain responses to the insult were stronger on the left side of the brain than on the right side of the brain, indicating that anger involves not only negative feelings about the other person but also a motivational desire to address the insult.
Other psychophysiological measures, including heart rate, blood pressure, respiration speed, skin temperature, and skin conductance, assess the activity of the sympathetic and parasympathetic nervous systems. The electromyograph (EMG) assesses muscle responses in the face. For instance, Bartholow and his colleagues (2001) found that EMG responses were stronger when people read information that was unexpected or unusual than when they read more expected material, and that the responses were particularly strong in response to negative events. Still other physiological measures, such as amount of cortisol, involve determining what chemicals are in the bloodstream—for instance, to evaluate biochemical reactions to stress.
Although collecting psychophysiological measures can be diffi cult because doing so often requires sophisticated equipment and expertise and the interpretation of these measures may yield ambiguous results (For instance, does an increase in heart rate mean that the person is angry or afraid?), these measures do reduce reactivity to a large extent and are increasingly being used in behavioral research.
