Temperament

Definition

Individual differences in human motivation and emotion that appear early in life, usually thought to be biological in origin. Temperament is sometimes considered the biological or physiological component of personality, which refers to the sum total of the physical, emotional, mental, spiritual, and social dimensions of an individual.

History

Ancient Greek and Roman physicians invoked nature, claiming that the proportions of the various humors or fluids in the bodies influenced personality. They thought that there were four basic temperaments—sanguine (cheerful), choleric (irritable), melancholic (gloomy), and phlegmatic (apathetic)—which were determined by the predominance of blood, yellow bile, black bile, and phlegm respectively in the person's physical constitution. The ancient theory survives in the form of such expressions as "being in a bad (or good) humor."

The theory of four bodily humors did not survive the rise of scientific medicine in the seventeenth century as an explanation for differences in human temperament, but it has not been replaced by any single universally accepted theory of personality either. During most of the twentieth century, political ideology, discoveries about the learning or conditioning capabilities of infants, and the emergence of psychoanalytic theory, which emphasized the importance of early experience, all combined to discredit biological explanations for human motivation and emotion. Nurture and socialization became the favored explanations of differences in temperament.

There was, however, a resurgence of interest in the contribution of temperament to children's development after the 1950s. Temperament came to be summarized as the biological dimension of personality. It was seen as a predisposition that allows two individuals to experience the same objective event very differently within the range of normal behavior and development.

Specific approaches to temperament

THE NEW YORK LONGITUDINAL STUDY Suspecting that inherent individual differences among their young patients contributed to their developmental paths, two child psychiatrists, Alexander Thomas and Stella Chess, designed a study that challenged the nature-nurture dichotomy. Beginning in 1956 and ultimately publishing their research in Temperament and Development in 1977, Thomas and Chess collected longitudinal data from over 100 children, following them from infancy through early adulthood. Using extensive clinical interviews to gather information about children's behavior as well as parents' values and expectations, they examined what they termed the goodness of fit between the individual child and his or her environment.

Thomas and Chess found that children could be rated on each of nine dimensions even in infancy:

• Activity level: The child's general level of energy and movement—whether he or she is quiet, always "on the go," or somewhere in-between.
• Rhythmicity: The child's regular biological patterns of appetite and sleep—whether the child gets hungry or tired at predictable times.
• Approach/withdrawal: The child's usual response to new people or situations—whether the child is eager for new experiences or shy and hesitant.
• Adaptability: The child's ability and pace in adjusting to changes in schedules or transitions from one activity to another.
• Threshold of responsiveness: The child's level of sensitivity to such physical stimuli as sounds, smells, and lights. For example, some children are easily startled by sudden noises while others are less sensitive to them. Some children are pickier about food than others.
• Intensity: The child's responses to people or events. Some children react strongly and loudly to even minor events while others are less demonstrative or openly emotional.
• Quality of mood: The child's overall worldview, whether positive or negative. Some children tend to focus on the negative aspects of a situation while others are more positive or hopeful. Some children tend to approach life in a serious or analytical fashion while others respond to their immediate impressions of situations.
• Distractibility: The child's ability to pay attention to tasks or instructions even when the child is not particularly interested in them. Some children have shorter attention spans than others.
• Persistence: The child's ability to continue with an activity in the face of obstacles or problems. Some children are more easily discouraged by difficulties than others.

Thomas and Chess combined the patterns of children's ratings on each of these nine dimensions to distinguish three major temperamental types:

• Easy children: About 40 percent of the NYLS sample displayed a temperamental profile marked by regularity, ease of approach to new stimuli, adaptability to change, mild to moderate mood intensity, and a generally positive mood. This profile characterizes what Thomas and Chess call the easy child.
• Difficult children: About 10 percent of children showed a very different profile and were called difficult children. They had irregular patterns of eating and sleeping, withdrew from new stimuli, did not adapt easily to change, and reacted intensely to changes. Their overall mood was often negative.
• Slow-to-adapt children: Children who were slow to warm up comprised the third temperamental group, about 15 percent of Thomas and Chess's sample. These children tended to withdraw from new stimuli and had difficulty adapting to change, but their reactions were of mild intensity and gradually became either neutral or positive with repeated exposures to the new event or person.

Some researchers prefer the terms flexible, active or feisty, and cautious instead of the somewhat judgmental terms of easy, difficult, and slow-to-adapt, respectively.

Clearly, these three temperamental types that Thomas and Chess identified did not include all of the variations seen in children across the entire sample. About one third of the children showed mixed profiles. Nonetheless, these temperamental classifications became highly influential in child development research. Perhaps the greatest contribution of the NYLS, however, was Thomas and Chess's emphasis on "goodness of fit"; that is, they maintained that the child's temperament by itself was not the most important consideration in his or her growth and development, but the extent to which that temperament agreed with the values, expectations, and style of the child's environment, whether family, childcare setting, school, or culture. For example, a quiet and serious child fits in well with a family of scholars or intellectuals, whereas an intense, active, and easily distracted child may not be accepted as readily in the same family context. In terms of culture, some ethnic groups place a high value on self-control and relating well to others, while other groups emphasize assertiveness and independence. A child who has a high energy level and reacts intensely to persons and events will have a better fit with the second group than with the first. The notion of goodness of fit also helps to explain why some children in a given family seem to get along better with their parents than their siblings do. Even though temperament is thought to be rooted in biology, different children in the same family may have very different temperaments.

TRAIT APPROACHES Some approaches to the study of temperament emphasize traits; that is, they assume that temperamental qualities can be rated as persisting within individuals across time in a variety of situations. In 1984, as published in their book, Temperament: Early Developing Personality Traits, Arnold Buss and others considered temperaments to be heritable and stable personality profiles—profiles that are genetically influenced and relatively unchanging over time. These researchers used maternal questionnaires to gather information on children's emotionality, activity, and sociability, traits they regarded as the fundamental dimensions of temperament. Interestingly, Buss and Plomin suggested that children who are rated as extreme on these dimensions may be qualitatively different from those whose scores lie closer to the middle.

Basic emotions were at the core of H. Hill Goldsmith and Joseph Campos's conception of temperament. In 1983, in an essay included in Socio-Emotional Development, they described temperament in terms of individual differences in experiencing and expressing such primary emotions as anger, fear, and pleasure. Goldsmith and Campos, however, emphasized the speed and intensity of children's responses to stimuli as well as the specific emotions involved. Their evaluations were based on three measurements: threshold (the amount of stimulation the child requires before responding); latency to respond (how rapidly the child reacts to the stimulus); and intensity of response.

In 2004, Mary Rothbart emphasized reactivity and self-regulation as core processes in organizing temperamental profiles. These processes, she believed, can be seen in six significant infant behaviors: smiling; distress when confronted by limitations; fear; activity level; soothability, and duration of orienting (how long the baby plays with or pays attention to a single object). Her Infant Behavior Questionnaire (IBQ), which was developed in the early 1980s, remained, as of 2004, one of the most widely used methods of assessing temperament in infants between the ages of three months and 12 months. In the first version of the IBQ, published in 1981, parents were asked to rate the frequency of these temperament-related behaviors in their child over a two-week period. The revised version of the IBQ, known as the IBQ-R, was developed by Rothbart and her colleague Masha Gartstein in the early 2000s. The IBQ-R expanded the original six measures of temperament to 14. The new measurements include the following:

• Approach: The infant's excitement and looking forward to a pleasurable experience or activity.
• Vocal reactivity: The baby's level of vocal responses to stimuli in its daily routine.
• Perceptual sensitivity: The infant's ability to detect low-intensity stimuli in its environment.
• Sadness.
• High-intensity pleasure: The infant's reactions to pleasurable stimuli or activities of high intensity, such as loud music or bright lights.
• Low-intensity pleasure.
• Cuddliness: The infant's physical and emotional responses to being held or cuddled by a parent or caregiver.
• Rate of recovery from distress: How long it takes the infant to return to a normal level of emotion after an exciting or upsetting experience and how readily the child falls asleep.

In contrast to Goldsmith and Campos, Rothbart emphasized cognitive processes in children as the key to understanding temperament rather than emotions by themselves. For Rothbart and her colleagues, the infant's ability to focus its attention is the basis of its later ability to regulate its reactions to people and events. In Rothbart's view, what she calls the attentional system allows the child to regulate his or her outward behavior as well as internal reactions to stimuli. As children mature, they develop the ability to turn their attention to alternative strategies when they are frustrated and to make plans in order to achieve their goals. Different patterns of self-regulation in turn help to explain differences in temperament.

Goldsmith and Rothbart collaborated to develop an assessment tool to gauge temperamental dimension based on systematic observations of behaviors elicited under standard laboratory conditions (for example, how a child reacts to a mechanical spider). The development of an observational protocol or test for assessing temperamental characteristics offers an advantage over reliance on questionnaires. When parents describe their children's behavior, they are influenced by their feelings about the child as well as their observations. In addition, the parents' reports include many sources of information such that reports of the child's behavior cannot be easily separated from the parents' biases, values, or expectations.

TYPE APPROACHES Another major approach to the study of temperament distinguishes among types of people characterized by different patterns of behavior. In the 1990s, in Galen's Prophecy, Jerome Kagan and his colleagues studied two types of children whom they defined as inhibited and uninhibited (or exuberant) respectively. Kagan's group studied the development of these two types of children through adolescence as well as the infant profiles that predicted the children's behavior at later ages. At early ages, inhibited children cling to their mothers and may cry and hesitate when confronted with unfamiliar persons or events. These children appear to be timid and shy and represent about 20 percent of volunteer Caucasian samples. Uninhibited or exuberant children, on the other hand, approach new events and persons without hesitation or trepidation. They appear fearless and sociable and represent about 40 percent of volunteer samples. Kagan's observations of these children over time indicated that these characteristic profiles tended to continue, although the display of temperamental tendencies varied in accordance with the child's developmental level. An older inhibited child or teenager, for example, may not cling to his or her mother or cry when coming to an unfamiliar laboratory but may hesitate to talk to the examiner and may smile infrequently.

Interestingly, Kagan found that the behavioral profiles of these children were accompanied by physiologic profiles that suggested different levels of reactivity in the children's central nervous systems, particularly in regard to fear and stress reactions. Inhibited, compared to uninhibited, children tended to have higher and more stable heart rates, higher levels of stress-related hormones like cortisol and norephinephrine, larger changes in blood pressure in response to stressors, and measurable tension in their voices when speaking under mildly stressful conditions. These differences seemed to support the contention that temperamental categories have a biological dimension.

Although young infants are not sufficiently mature to demonstrate timidity in response to new experiences, the reactivity of the structures in the human nervous system that are thought to underlie inhibited and uninhibited temperaments may appear at early ages. When infants are exposed to variations in the sights and sounds in their environment, some become aroused and demonstrate this arousal by moving their arms and legs and fretting or crying. Other infants remain calm, relatively motionless, and do not cry. Those who are highly reactive to stimulation tend to become inhibited in their reactions to novelty and uncertainty at later ages. Those whose reactivity level is low in infancy tend to grow into children who remain relaxed in novel situations so that they appear outgoing and uninhibited.

MALLEABILITY OF TEMPERAMENT Malleability refers to the extent to which temperament can be influenced or reshaped by later life events. The reader should note that the continuity of temperamental profiles from infancy through later ages is a group phenomenon; that is, individual children may change and become more or less inhibited while the groups of children remain distinct on average. Neither temperament nor biology is destiny. Temperament and environment both influence development, although relatively few researchers have studied the interaction of these two influences as of the early 2000s.