Class Notes (806,783)
Canada (492,447)
Psychology (7,610)
PSYB30H3 (526)

6 - Personality and Genetics Lecture Outline.docx

3 Pages
Unlock Document

University of Toronto Scarborough
Connie Boudens

6 - Personality and Genetics (Relevant) Cell biology basics Cell nucleus contains DNA  Carries genetic information  Controls growth and development  23 pairs of chromosomes o Consists of 4 bases - ATCG  One gene = millions of bases arranged in a sequence Gene expression: genotype vs phenotype  Genotype = specific genetic makeup o "what you have" o The sequence of bases in all your DNA o Made up of all alleles  Allele = gene variants  Phenotype = how genetic makeup is expressed o "What you see" Forms of gene expression - Mendel: peas to determine gene expression • Dominant-recessive • one allele dominates  also referred to as Mendellian inheritance: two alleles – one dominant and one recessive • Codominance and incomplete dominance • neither dominant, or one dominant - doesn’t hide effects of other • Codominance: both expressed (both individuals are expressed) • Both white and red leaves • Incomplete dominance: combination expressed (a mixture of the two is expressed but the individual isn't expresssed) • Pink leaves seen • Polygenic • Many pairs of alleles create expression Role of Environment Phenotype = (consists of the following three things) 1. Genotype + environment 2. +gene-environment interaction 3. +gene-environment correlation Genotype-Environment Interactions  Impact of environment depends on genotype  Example: Religious upbringing reduces influence of genetic factors on disinhibition. Genotype-Environment Correlation  Differential exposure of individuals with different genotypes to different environments o Passive: Parents provide both genes and environment to children.  Child’s verbal ability and the number of books in home o Reactive / evocative: Parents (or others) respond to children depending on the genotype  Baby’s liking for cuddling and mother’s cuddling behavior o Active: Person with particular genotype seeks out environment  High sensation seekers expose themselves to risky environments  Passive decreases with age, active increases  Genotype-environment correlations can be positive or negative Table 6.5 Positive and Negative Genotype-Environment Correlations Type of Correlation Genotype Environment Positive High High Positive Low Low Negative High Low Negative Low High Behavioural Genetics  Attempt to determine % of individual differences in a trait due to genetic and % due to environment  Determine the ways genes and environment interact and correlate  Determine what relevant env. factors are. Heritability : amount of individual difference in trait due to genetic differences. Environmentality extent to which individual differences are due to environmental differences Misconceptions About Heritability  Heritability CANNOT be applied to single individual o Only applies to group-level variation  Heritability NOT constant or immutable o Environment homogenous - heritability higher o Environmental variations increase - heritability will be lower o Even highly heritable traits modifiable by env.  Heritability NOT a precise statistic – think estimate Behavioral Genetics Methods 1. Selective Breeding  with animals  Can only occur if a desired trait is heritable  Done using animals
More Less

Related notes for PSYB30H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.