 The
research of emotions and temperament Genetics of Emotional
Ontogeny (GEO) project includes multi-method, comprehensive
assessment of emotion and temperament as well as selective
assessment of cognition, motor development, physiology,
social interaction, and the home environment from birth
to age 3 years. The methods include lab-based elicitation
of behavior, home observation, testing by examiner,
telephone interviews, diaries, narrative constructions,
questionnaires, hospital records, biochemical assays
(cortisol), and central (EEG) and peripheral (cardiac)
psychophysiology. The goals of GEO project fall into
two categories: (1) developing emotional individuality
and its correlates, and (2) genetic and environmental
underpinnings of emotional individuality and other domains
of development. A follow-up study combines emotional
and physiological aspects of development with twins
ages 6-9 years.
There are four broad aims of the research on emotions
and temperament. Concerning elucidating emotional
individuality, an initial aim is to map the onset
and early developmental course of affective responses
such as the social smile, wary reactions to strangers,
initial empathetic responses, inhibition, embarrassment,
guilt, and pride. A second aim is to investigate individual
differences in the timing of emotional development.
Potential correlates include physical, motoric, physiological,
cognitive, and social factors. For example, GEO will
provide new evidence crucial to one long standing
question in infancy research: Does emotional development
depend upon cognitive transitions (Biringen, Emde,
Campos, & Appelbaum, 1995; Decarie, 1965; Haith
& Campos, 1977; Harris, 1989; Kagan, 1981)? It
will also provide evidence crucial to a more contemporary
question: Does emotional development depend on motoric
transitions (Bertenthal & Campos, 1990; Fogel
& Thelen, 1987)? A third aim is to verify other
researchers’ discoveries of periods of rapid,
cross-domain, developmental change, interspersed with
slower growth. A fourth, major aim is to investigate
the functional significance of temperament. We equate
temperament operationally with individual differences
in emotional expression (Goldsmith, 1993) or emotional
biases (Malatesta, 1990). This addresses the functional
significance of the timing of emotional development.
Temperament will also be related to the array of physical,
motoric, physiological, cognitive, and social factors
assessed in the project.
The second category of goals includes at least seven
behavior-genetic issues. In essence, each of the aims
mentioned in the previous paragraph can be investigated
in a genetically informative way. (1) Several constructs
in the project have not been subjected to simple univariate
biometric analysis (e.g., frontal EEG asymmetry; infant
cortisol levels; MacArthur Communicative Development
Inventory). (2) If the timing parameters of emotional
development (ages of onset, times of transition) are
more similar in identical cotwins than in fraternal
cotwins, genetic variance is implicated. (3) Documentation
of common genetic bases of physiology and behavior
would be an important step toward a process-oriented
understanding of the genetic basis of the emotional
differences that underlie much variation in normal
range behavior and susceptibility to behavioral problems.
The analysis of genetic and environmental covariance
between temperamental inhibition and frontal EEG asymmetry
is only one example of the many multivariate quantitative
genetic analyses that will be pursued. Another would
involve self development and self-conscious emotions.
Combining (2) and (3), we can also (4) use the twin
design to discover if a common genetic basis for the
covariance in timing of cognitive and emotional transitions
exists. (5) Besides the ordinary questions of phenotypic
convergence among the many measures of constructs,
multitrait, multimethod genetic covariance analyses
can be done. (6) The longitudinal design allows us
to study genetic bases of stability and change. (7)
Finally, the study incorporates several specific measures
of the environment (e.g., emotional atmosphere of
the home, parental personality, marital quality, home
characteristics, sibling conflict, stressful life
events, child-rearing beliefs and practices), and
these can be used to elucidate the abstract shared
and nonshared environmental variance components.
Additionally and importantly from our twin families’
viewpoints, we investigate the ecology of twinship
and provide useful information to the participating
families. The foundation will be laid for future extensions
toward genetic linkage and association studies of
early temperament (using fraternal twins) and toward
following the twins through the transition to school.
List
of Assessments at each Major Phase of GEO |
