Hoofdstuk 11 uit The Cambridge handbook of
personality psychology van Corr en Matthews. Opdracht
2.3.1
INTRODUCTION
Temperament is linked to the structure and function of the nervous system
and to the experience of the organism. When we measure the person's
readiness to anger, to seek reward, to focus and switch attention, etc., we
are measuring temperament and these in turn are linked to brain
networks. Hyperreactivity to an unexpected, novel or intense stimulus is
also a measure of temperament, important in understanding the
development of behavior problems in children and psychopathologies of
stress and attention in adults (Rothbart, 2011; Zentner & Shiner, 2012).
Studies of resting state MRI have allowed tracing human brain changes
from birth (Gao et al., 2016), allowing examination of the development of
attention and other networks early in life. The advance of epigenetic
studies (Meaney, 2010) has offered a framework for thinking about how
the environment and gene expression work in concert to produce the
pattern of connectivity unique to the individual.
It is important to separate temperament tendencies from more general
personality traits, because temperament allows for an understanding of
the developmental processes that shape personality and provides
particularly close links with neuroscience. We have defined
*temperament* as constitutionally based individual differences in
emotional, motor, and attentional reactivity and self-regulation, showing
consistency across situations and relative stability over time (Derryberry &
Rothbart, 1997; Rothbart & Derryberry, 1981). The term “reactivity” refers
to the latency, rise time, intensity and duration of the person’s
responsiveness to stimulation. “Self-regulation” refers to processes that
serve to modulate reactivity, including orienting and effortful attention,
along with motor tendencies toward actions of approach, withdrawal,
inhibition, and self-stimulation.
Temperament does not refer to a single system, but to multiple systems
that may inhibit or facilitate each other’s expression (Rothbart & Sheese,
2007). Consider, for example, how fear inhibits approach tendencies and
withdrawal inhibits fear. We are increasingly finding mechanisms of
individual differences in reactivity and self-regulation at levels ranging
from genes to culture. We do not expect temperament to remain stable
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,across a life (Rothbart & Derryberry, 1981). If temperament is defined as
reactivity and self-regulation, then the expression of temperament is in
relation to some situational change. Experiences in strange situations with
varying social demands and challenges require different adaptations.
These depend on the constitution of the child, so that some children, when
approached by a stranger, cry out in fear while others treat physical
contact with pleasure. However, if the child is not confronted by these
kinds of stimuli, any tendency to react will not be experienced and
practiced. There is now strong evidence that abuse and neglect can
increase distress proneness in children, and that traumatic experiences of
military combat also lead to disruptions of reactivity and self-regulation. A
developmental analysis would be most helpful here. A child may have a
disposition to distress to overstimulation that is exacerbated by trauma
occurring in both childhood and adulthood.
Temperament also influences children and adults through their perceptions
of how people see them. Given the social construction of the self,
temperament thus influences how we see, describe and behave toward
others, and ourselves. Temperament also is pivotal in the study of the
development of psychopathologies of behavior, stress and attention across
the lifespan (Rothbart, 2011; Zentner & Shiner, 2012).
Recent personality research has often employed the Big Five or Five-Factor
models of personality. The five (or three to seven) factors are extracted
from multivariate analyses of trait descriptive adjectives and other
personality items (Digman & Inouye, 1986). The Big Five approach has
been based on the premise that all significant variations in personality are
represented in language. Although of considerable interest, these models
are incomplete. An infant personality researcher is immediately confused
by the titles of the factors: Have you ever seen a conscientious infant? A
neurotic infant?
The traits do not describe individual differences in early life, nor do they
support the study of a person's complex adaptations during the course of
development. We have found particularly helpful the work of theorists and
researchers with closer links to temperament and the nervous system,
including Pavlov, Eysenck, Nebylitsyn and Gray, and those in their
research traditions. In the first short historical section of this chapter, we
discuss these psychobiological traditions. We also provide a brief history of
more recent temperament concepts and research. We then move to
consider the biology of temperament in the structure of brain networks
and their genes as exciting possibilities for the future.
HISTORICAL PERSPECTIVES
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,Temperament has been recognized since ancient times (Feng & English,
1972; Rothbart, 2011) in China and India. In this section, however, we start
with the typology of temperament described by Greco-Roman physicians,
who linked temperamental characteristics to Hippocrates’ model of the
humoral constitution of the body (Diamond, 1974). In this fourfold
typology, the melancholic person, quiet and moody, was seen as having a
predominance of black bile; the choleric person as touchy, aggressive and
active, with a predominance of yellow bile; the sanguine person as
sociable and easygoing, with a predominance of blood; and the phlegmatic
person, calm and even-tempered, with a predominance of phlegm. The
typology was also related to psychopathology, with links between
melancholia and depression, and the choleric temperament and
aggression. Use of the fourfold typology persisted throughout the Middle
Ages and the Renaissance, and can be found in the writings of Kant
(1798/1978). It continues to be linked to temperament and personality
research.
Pavlovian Efforts
In more recent times, a psychobiological research tradition on
temperament has developed in both Eastern Europe and the West. The
Eastern European tradition had its roots in Pavlov’s laboratory, where
temperamental differences were observed in studies of conditioning.
Individual dogs, given names, were repeatedly observed in a variety of
experimental settings. The researchers noted consistent differences in the
temperament of the animals, which Pavlov linked to qualities of the central
nervous system revealed in their conditioning responses. Pavlov proposed
that dogs who could continue to increase the strength of a conditioned
response under high-intensity or prolonged stimulation possessed a
“strong” nervous system; those who lost the response more easily were
said to have a “weak” nervous system. Later research by Nebylittsyn and
Gray (1972), using laboratory and drugs studies of human, observed that
individual with weak nevous systems also showen lower sensory
thresholds than those with strong nervous systems. However, problems
developed for the tradition when the nervous system properties, though
once thought to be general, appeared to be highly dependent on the
specific stimuli used and the specific responses measured in the laboratory
(Strelau, 1987).
Questionnaire Studies
Early studies of temperament in the West focused on identifying the
structure of individual differences through the analysis of questionnaire
items. For example, Heymans and Wiersma (1906) asked 3,000 physicians
to each observe a family (parents and children) and fill out a questionnaire
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, on each family member. Using the factor-analytic procedures of that era,
they identified three general factors and proposed eight types of
temperament. Webb (1915) and Burt (1939) also applied early forms of
factor analysis to questionnaire items written to assess the individual's
emotionality, self-concept, and intellect. Their work revealed factors such
as Extraversion–Introversion, Emotional Stability–Instability (later called
Neuroticism by Hans Eysenck), and in Webb’s work, a factor of volition or
will, which anticipated the later concept of Effortful Control. Hans Eysenck
(1947), like Pavlov, proposed a physiological basis for temperament. His
model initially related Extraversion–Introversion to cortical excitation and
inhibition, and Neuroticism to limbic system functioning. Later, Eysenck
(1970) presented a revised model of temperament based on the ascending
reticular activating system and individual differences in arousability. Gray
(1978) extended Eysenck’s theory by proposing individual differences in
behavioral activation and inhibition, and tendencies toward fight-or-flight
responses. Gray’s model remains one of the major psychobiological
theories of adult temperament, alongside models introduced by Cloninger
and colleagues (1993), Depue and Iacono (1989), Panksepp (1998), and
Zuckerman and colleagues (1996). These models have significantly
influenced modern temperament research by linking it to personality,
although they offer limited insight into development.
Observations of Children's Development
Observational studies of children came later than adult work. Gesell’s
(1928) and Shirley’s (1933) longitudinal studies established the normal
sequences of motor and mental development. At the same time they
noted striking temperamental variability among the children they
observed (Gesell, 1928, as cited in Kessen, 1965; Shirley, 1933). In mid-
century, Bergman and Escalona (1949) identified children who were
strongly reactive to low intensities of stimulation in one or more sensory
modalities, especially sight, hearing, and touch, and Escalona’s (1968)
powerful concept of “effective experience” argued that simply
characterizing an environmental event does not accurately portray a
child’s experience of it. The social world is not experienced in the same
way for all children, as can be seen when a vigorous hug from a visitor
brings active pleasure to some infants but distress to others. The child’s
temperament also tends to evoke different responses from adults
depending on the adult’s attitude and expectations about proper child
behavior. Temperament is further linked to the child’s adaptations to the
physical and social world (Rothbart, 2011).
In Europe, observation studies of temperament in infancy were also
underway. Beginning in 1950, Meili studied three- to four-month-old Swiss
infants’ responses to unfamiliar stimuli and coded infants’ reactions from
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