5- Nature and Nurture of Psychopathology Flashcards
What is temperament
Individual differences in emotion, activity level, and attention that are exhibited across context and present from infancy
Types of adoption designs testing nature vs nurture
- Biological and adoptive parents and adoptees
- Adoptive vs. non-adoptive families
Types of twin designs testing nature vs nurture
- MZ vs. DZ twins
- Twins reared apart and together
Adoption design limitations
- Adoptees are not placed randomly into adoptive families, they tend to be chosen to provide environments that are low-risk
- Adoption studies may not be generalisable to the population at large
- Prenatal influences are not taken into account
- Adoption (especially, adoption at birth) is an unusual event in itself
Adoption study for child temperament found
Higher correlation between adoptees and their biological parents than adoptive parents
Twin studies for child temperament found
Consistently found that MZ co-twins are more similar than DZ co-twins across a wide variety of temperament dimensions including: emotionality, activity, sociability, attention/persistence, etc
Twin design limitations
- Assumption that environments are similar for identical and fraternal twins, monozygotic twins share more similar environments -both prenatal and postnatal
- Twin studies may not be generalisable to the population at large, eg twins are more susceptible to prenatal trauma leading to mental retardation
- MZ twins may not be 100% genetically identical, there are various biological mechanisms that can lead to genetic differences between MZ twins
What is heritability
- The proportion of variance in a population attributable to genetic differences between people
- It’s a statistical estimate for a population (not an individual) studied
- It does not refer to particular genes
- Estimate applies only to a particular population living in a particular environment at a particular time
- Estimate does not account for a complex interplay between genetic an environment factors
Twin study of child temperament
Lemery-Chalfantet al, 2013
- 807 pairs of twins, mean age 8 years (301 MZ; 263 same-sex DZ; 243 opposite-sex DZ) from Wisconsin Twin Project
- Parent telephone interviews, home visits
- Finding 1: effortful control, negative affectivity, extraversion show high heritability: 54%, 79%, 49%
- Finding 2: Home environments (how chaotic and unsafe they are) are also under genetic influence (heritable) and affect personality (extraversion)
- Conclusion: Parents’ temperament can influence child temperament through genetic transmission and through home environment that they create
Developmental psychopathology uses what two approaches
- Clinical diagnostic approach
- Empirical quantitative approach
What is the clinical diagnostic approach
Psychopathologies are considered to be discrete categories defined on the basis of criteria proposed by experts (DSM-IV; ICD-10)
What is the empirical quantitative approach
Psychopathology symptoms are assessed on a continuous scale, with the disorders being the extreme ends of the distribution
What are examples of Internalising psychopathology
Depression, Anxiety
What are examples of Externalising psychopathology:
Conduct problems, ADHD (attention problems, impulsivity)
Facts about psychopathology in children and youth
- Major public health issue
- Very common: 10-25%
- Have early onset: 75% before age 25
- Are chronic: 22-46% (up to 60% in young people)
