Biological Bases of Personality and Intelligence Flashcards
What is genotype?
The internal genetic code for maintaining a living individual
What is phenotype?
The outward manifestation of the individual
What is genetic heritability?
The assessment of the extent that any phenotype is passed on from children to children from genes
What influence does the environment have?
On heritable variability and lower shared variance
What does low variability between the parent and child mean?
High proportion of shared variance the characteristis
What are certain behaviours linked to?
Certain personality traits which are heritable
What are the three things that influence personality?
Social theories (environment)
Genes (variation in brain structure and function
Gene-environment interaction
What are the issues of genetic analyses?
Biological mechanisms that they can identify with are not specific unless looking at the effect on individual genes
What is a lesion study?
A method for studying personality= investigation of the brain that has been impacted by an event
Who studied brain injury and personality?
Forbes et al
What did Forbes et al find?
Damage to the left dorso lateral pre frontal cortex associated with high neuroticism and low conscientiousness
What do the Forbes et al findings suggest?
That N + C rely on a common neural structure
What is a criticism of Forbes et al?
Study doesn’t indicate anything functional unless using functional imagery
Who looked at cortical folding?
Schultz et al
What did Schultz et al find?
High levels of neuroticism associated with low cortical folding of the left dorsal lateral pre frontal cortex. Structural changes associated with neuroticism=m
Who looked at structural brain images?
Ejindhoven et al
What did Ejindhoven et al find?
Neuroticism companied with cortico-limbic brain structures
High N scores predicted by thinning of the left orbital frontal cortex and smaller volume of the right amygdala
What evidence supports Ejienhoven et al?
The limbic system being involved in emotional activity + the orbital frontal cortex being associated with personality traits
What does gene expression do?
Control brain development in the limbic system
What are the traits of gene expression?
Complex + coordinated
What occurs to genes?
Need to be transcribed to make mRNA which is translated to proteins
What are the components of chromosomes?
Long strand of DNA spaced with non-functional sequences
What are the contributions to a trait?
Genetics, shared environment + non-shared environment
What are the types of studies?
Twin, adoption + family
Who found the three types of studies?
Plomin et al
What are twin studies?
MZ and DZ comparison
What are adoption studies?
Personality compared with adopted children and adopted parents and biological
Which journal article looked at adoption studies?
Goldsmith 1983
What did Goldsmith find?
Adoption studies provide estimates for genetic and environmental influences
What are family studies?
Observation, interview and questionnaire, but similarities might be due to environmental
What are the comparisons between twin, family + adoption studies?
Between siblings, twins, reared together or apart to examine the extent of genetic environmental effects
What are the three types of genetic variance?
Additive, dominant + epistatic
What is additive genetic variance?
The total effect on a trait from one or more gene loci
Each locus contributes to a trait (measurable)
What is dominant genetic variance?
Certain genes are expressed and others aren’t
What is epistatic genetic variance?
Genes + environment interact and particular genes will be expressed in certain circumstance
Who spoke of the non shared environment characteristics that influence personality?
Harris
What are the non shared environment characteristics that influence personality?
Context specific socialisation
Outside the home socialisation
Transmission of culture via group processes
Group processes that widen differences between social groups
Group processes that widen differences among individuals within the group
What is context specific socialisation?
Children learn behaviours at home and outside but become less influenced by family as they get older