TEMPERAMENT

Three Common Elements of Temperament Characteristics

The first factor common to all temperament characteristics is that these individual differences are present at birth. Sigmund Freud was the first psychologist to discuss personality development. The purpose of his theory, however, was to explain the common human experience. Freud argued that all children were born with biological drives (e.g., hunger, thirst) that need to be satisfied in order to ensure personal survival. Three mental structures (the id, the ego, and the superego) emerge during childhood and struggle with each other to create the individual's personality. According to Freud, personality differences are not present at birth. Instead, these differences emerge during childhood as each child resolves internal conflict in different ways and in different family contexts. By adolescence, children have developed unique coping styles that are stable into adulthood. Temperament researchers, on the other hand, argue that differences in reactions to the world are present at birth. In addition, few believe that children are constantly struggling to resolve internal conflict during childhood. Children are born with unique behavioral styles that influence their development from the womb until death.

The second element common to all temperament characteristics is that these differences are inherent in the person. Temperament is a biologically based reaction to the world. This does not mean that all temperamental differences are genetically inherited. This is the foundation of Arnold Buss and Robert Plomin's EAS theory of temperament, with EAS standing for the traits found to be heritable during infancy (emotionality, activity, and sociability). Other researchers, however, also include prenatal influences on children's behavior. The idea that traits are biologically based does not mean that these characteristics are resistant to environmental influences. All temperament theorists argue that social experiences can and will change a child's temperament. Inherent simply means that these behavioral styles are not due to parenting. Infants' unique reactions to the world have biological roots. For instance, many children born to mothers addicted to drugs have very difficult temperaments; these children cry often, are hard to console, and do not like to be held. Their behavior is thought to be due to the influence of the drugs on the developing fetus in the womb. Other children may inherit from their parents a tendency to be emotional or shy.

As early as 1699, the philosopher John Locke maintained that children are born with different behavioral tendencies. He also believed that the environment was the strongest force in development. To Locke, social experiences, not temperamental differences, shaped behavior across development. This was the predominant view of children's development until the 1960s and 1970s. During this time, Alexander Thomas and Stella Chess published their classic books about the role of temperament in parent-child relationships and children's social and emotional development. Thomas and Chess argued that children's behavioral problems do not always stem from bad parenting. Instead, some children come into this world with temperament styles that make disciplining them a challenge. Even competent, caring parents may have difficult children and these parents need help learning how to manage their sons and daughters.

Other child psychologists at this time also asserted that children are born equipped with behavioral biases and abilities that affect later development. The cognitive psychologist Jean Piaget described infants as active participants in their own experiences who are motivated to learn how to adapt in their environments. By the end of the 1980s, the child was no longer seen as a piece of clay to be molded into an obedient citizen, but as a force to be guided into a competent adult. It was in this intellectual context that the notion took hold that children are born with unique temperament characteristics.

The third component of all definitions of temperament is that behavioral styles are relatively stable across development. Temperament characteristics can and will change in response to parenting and other social forces. The idea is that the early roots of adult personality can be seen from the beginning. Several studies have included groups of individuals who were followed from birth to adulthood. The findings from these studies regarding stability are mixed. Children's temperament traits do appear to be quite stable through infancy and into childhood. Jerome Kagan and his colleagues studied two extreme groups of children from infancy to adolescence. Members of the first group, behaviorally inhibited children, were very shy and fearful in unfamiliar situations. Members of the second group, behaviorally uninhibited children, were very gregarious and assertive in novel settings. The researchers found that the inhibited children were at greater risk for later social and emotional problems compared to the uninhibited children.

Others have found that children who withdraw from situations or who throw tantrums have more marital and work-related problems in adulthood compared to other children. Temperament measures are good tools to help uncover early adjustment problems. Predicting adult personality from infant temperament, however, is not as easily achieved for those in the middle range compared to those at the extreme ends. Some children change in response to their experiences with their parents, teachers, and peers. In addition, children begin to exert conscious control over their behavioral tendencies during childhood. Part of healthy development is learning how to adapt to the demands of different contexts. Some active children learn restraint and some emotional children learn peacefulness.

Measuring Temperament

While researchers tend to agree on the basic definition of temperament, they differ on the types of temperament styles they investigate. According to McCall, most temperament studies focus on four dimensions: activity, reactivity, emotionality, and sociability. Activity is the intensity and rate of a child's movement and speech. How much does the child move around during play or at her desk at school? Reactivity is the intensity of a child's approach or withdrawal from a situation and how long the child is interested in and stays in the situation. How much does a child withdraw from novel toys or new situations? Emotionality is the degree to which a child expresses negative or positive emotions and how often she expresses them. Does a child get upset easily or become angry quickly? Sociability is the tendency to initiate social contact and the preference to be with others. Is the child friendly?

Not all temperament characteristics fit neatly into these four dimensions. Shyness, for example, has been investigated as an aspect of reactivity (i.e., the tendency to withdraw from new social situations) and as the opposite end of sociability (i.e., the tendency to not want to be around people). While many researchers have focused on one or more of these dimensions, others have categorized children based on combinations of traits and styles.

Thomas and Chess divided children into three categories based on nine temperament dimensions: activity level, approach-withdrawal in new situations, adaptability, threshold of responsiveness, intensity of reactions, quality of mood, distractibility, persistence, and rhythmicity of biological functions (e.g., sleeping, feeding, needing to be changed). They were interested in the "goodness-of-fit" between the children's characteristics and their social environments. Forty percent of the children in their study were classified as "easy" babies. These children adapted easily to new situations, were sociable and playful, and had regular biological functions. These children were not too reactive or emotional, and so they were easy to parent. Another 15 percent of the babies fell into the "slowto-warm-up" category. These children withdrew from new situations somewhat, took a little longer to adapt to environments, and were less active. They needed more attention and time compared to easy babies, but they adapted to their surroundings without too much trouble. About 10 percent of the infants were classified in the "difficult" temperament category. Children with difficult temperaments were very emotional, had irregular biological functions, and had intense negative reactions to new situations. These children were the most difficult to parent and required a great deal of effort, time, and patience. The remaining children fell into more than one category or could not be classified.

Dimensions of temperament are measured in a variety of ways. Parents are interviewed about their children's behavior at home, and teachers are interviewed about the children's behavior at school. Depending on the dimension being assessed, these adults may be asked about children's reactions to new toys or people (i.e., reactivity) or about their energy levels (i.e., activity). Parent and teacher reports of children's behavior may be limited to that context and influenced by their own perceptions of the world (i.e., they may be biased). So, scientists also use behavioral and observational methods to assess children's temperament. Activity level in infancy, for example, can be measured using a device that measures the number of times a baby's arms and legs move. Most of the time, trained researchers observe the children at home, at school, or in a novel environment (e.g., a playroom in a researcher's laboratory). Coders look for visible signs of the child's underlying temperament style. For example, a child who approaches an unfamiliar student on a school playground and talks to the new child would be coded as high in sociability.

Some dimensions of temperament have to be assessed in specific contexts. Reactivity and shyness, for instance, must be observed in novel situations because the behavior of interest may not appear in familiar contexts or may appear for only some children. For example, children who are withdrawn in unfamiliar situations are considered temperamentally shy. Children who are withdrawn in both familiar and unfamiliar situations, on the other hand, are considered anxious and possibly at risk for developing an anxiety disorder. Sometimes children's behavior is ambiguous, so researchers will measure changes in children's physiology as well. Shy children, for instance, tend to experience a higher heart rate when they are in new situations compared to when they are at home. Children are also asked to report their perceptions of their temperament style after around the age of eight. This is when most children are able to report their own behaviors and preferences in a reliable manner. Few studies, however, include self-report measures because most temperament studies focus on children in infancy and early childhood.

Biological Factors

Since theorists have argued that temperament has biological roots, many studies have focused on genetic and neurological correlates of different behavioral styles. Most (if not all) temperament dimensions appear to be moderately heritable, with shyness showing the highest heritability. That is, the more closely people are genetically related, the more alike they are in temperament. Much of the evidence supporting this conclusion comes from twin studies, which compare the behavioral similarity of monozygotic (identical) twin pairs to dizygotic (fraternal) twin pairs. Monozygotic twins inherit identical genotypes because they develop from the same fertilized egg. In contrast, dizygotic twins inherit, on average, 50 percent of their segregating genes. If genetic differences across people are associated with temperament differences across people, then identical twin similarity should be twice as high as fraternal twin similarity. Plomin and others found that this is true for temperament characteristics such as emotionality, activity level, sociability, and shyness.

Interestingly, some studies show that identical twins are more than twice as similar as both fraternal twins and other pairs of relatives (e.g., parents and their children and biologically related siblings). How could this be? David Lykken and his colleagues hypothesized that temperament (and personality) differences are associated with genetic effects that do not run in families. These genetic effects are the result of complex interactions across loci at the level of the genome and across behaviors at the level of the developing person. Only identical twins inherit all the genes associated with these higher-order interactions, and so they will be much more similar to each other compared to other pairs of genetically related relatives. Some social scientists maintain that high identical twin similarity on temperament measures is due to monozygotic twin assimilation effects (i.e., parents treat identical twins more alike compared to fraternal twins) or to measurement problems (i.e., measures are not sensitive enough to detect moderate to low fraternal twin or sibling similarity). Still, few researchers would argue that temperament is completely determined by the environment.

During the 1990s, the search for biological correlates of temperament differences expanded to include investigations of brain activation patterns. Scientists found brain activation differences between children who approach new situations (i.e., behaviorally uninhibited children) compared to children who withdraw from novel contexts (i.e., behaviorally inhibited children). Even though temperament styles appear to be linked to genetic, physiological, and neurological processes, temperament researchers still consider environmental factors to be very important.

Environmental Factors

Thomas and Chess argued that children's temperament characteristics interact with parenting to produce children's positive or negative adjustment. Their concept of the goodness-of-fit between the parent and the child is similar to the notion of attachment developed by John Bowlby. Attachment is the dynamic relationship between the child and the caregiver. Human infants are born vulnerable and need the security of a consistent, attentive, warm caregiver in order to feel safe enough to explore the world. Caregivers give children verbal and nonverbal clues about the nature of the environment and provide them with a secure base to return to when they feel anxious or threatened.

Mary Ainsworth advanced the attachment literature by creating a laboratory measure of attachment called the Strange Situation. During this procedure, the child and caregiver are separated and reunited several times in a laboratory playroom. During the separation episodes, the child is left alone with a strange adult or in a strange room for short periods. The level of distress the child exhibits after the caregiver returns is the index of the strength of the attachment relationship. Securely attached infants will become upset during separation, but can be easily consoled by the caregiver when reunited. Insecurely attached infants will show one of two different reactions to the situation. In one group, the insecurely attached infants showed little distress when left alone and freely interacted with a stranger. In a second group, the infants were very distressed when left alone and could not be comforted by their caregivers upon their return. Many temperament researchers have pointed out that the Strange Situation is not equally strange (or scary) for all children. Very emotional or shy children may react strongly to the novel context, while very sociable children may show no distress at all. Some researchers even contend that Ainsworth's measure of attachment is really assessing temperament styles. Attachment researchers counter that the procedure measures the relationship between the caregiver and the child, which is partly a reflection of how well the caregiver copes with the child's unique behavioral style.

Many social scientists believe that temperament and parenting are both related to children's development, but in different ways. For instance, in a study of more than a hundred infants, Grazyna Kochanska found that differences in the mother-child relationship predicted whether children were securely or insecurely attached, while the children's temperament style predicted which type of reaction they displayed in the Strange Situation.

In another study, Kochanska found support for Thomas and Chess's goodness-of-fit concept. Two different parent-child relationships when the children were toddlers predicted the development of conscience in children when they were five years old. Fearful children did better with mothers who used gentle discipline, while fearless toddlers did better with mothers who were very responsive. To Thomas and Chess, healthy development occurs when parents are able to work with a child's temperament and influence their child's reactions to the world. Socialization happens and parenting is important, but each parent-child relationship will be unique because each child is unique.

It is important to note that Thomas and Chess's studies in the 1960s and 1970s were based on the ideal characteristics for an infant reared in Western society. Culture also plays a role in the fit between the child and his environment. For instance, Mary Roth-bart and others have found that parents in the United States and the People's Republic of China described their children using the same dimensions. Chinese infants, however, were lower in activity level compared to American children, a finding that has been replicated in other studies. In addition, the implications of certain temperament styles for children's development differ across cultures. Shyness or behavioral inhibition is associated with adjustment problems in the United States and Canada; the same temperament style, however, is associated with healthy development in China. What is considered a difficult temperament style depends on the culture, context, and characteristics of the family.

See also: ATTACHMENT; PARENTING; PERSONALITY DEVELOPMENT

Bibliography

Asendorpf, Jens B. "Abnormal Shyness in Children." Journal of Child Psychology and Psychiatry and Allied Disciplines 43 (1993):1069-1081.

Buss, Arnold H., and Robert Plomin. Temperament: Early Developing Personality Traits. Hillsdale, NJ: Lawrence Erlbaum, 1984.

Cole, Michael, and Sheila R. Cole. The Development of Children, 4th edition. New York: Worth Publishers, 2000.

Goldsmith, Hill H., Arnold H. Buss, Robert Plomin, Mary K. Roth-bart, Alexander Thomas, Stella Chess, Robert A. Hinde, and Robert B. McCall. "Roundtable: What Is Temperament? Four Approaches." Child Development 58 (1987):505-529.

Kagan, Jerome. Galen's Prophecy: Temperament in Human Nature. New York: Basic, 1994.

Kochanska, Grazyna. "Multiple Pathways to Conscience for Children with Different Temperaments: From Toddlerhood to Age Five." Developmental Psychology 33 (1997):228-240.

Kochanska, Grazyna. "Mother-Child Relationship, Child Fearfulness, and Emerging Attachment: A Short-Term Longitudinal Study." Developmental Psychology 43 (1998):480-490.

Lykken, David T., Matt McGue, Auke Tellegen, and T. J. Bouchard. "Emergenesis: Genetic Traits that May Not Run in Families." American Psychologist 47 (1992):1565-1577.

Rothbart, Mary K., Stephan A. Ahadi, and David E. Evans. "Temperament and Personality: Origins and Outcomes." Journal of Personality and Social Psychology 78, no. 1 (2000):122-135.

Thomas, Alexander, and Stella Chess. Temperament and Development. New York: Bruner/Mazel, 1977.

Shirley McGuire