Lecture 7 - Why are sibling's personality so diff - September 24 Flashcards
which of the big 5 is deemed the most confusing
openness to experience
what is O associated with
Assoc. w but not equal to IQ and cognitive abilities.
what does O focus on
More about cognition than social-emotional behaviors.
what does O relate to
Relates in powerful ways to motivation, values and life narratives – the personal as motivated agent and autobiographical author.
is O related to IQ
yes, it is the only trait related to IQ/education
Heritability of height = what
90%
An estimate of the proportion of variability in a given characteristic that can be attributed to what
genetic differences between people.
what are the Methods to explore heritability estimates for personality traits
Twin Studies
Adoption studies
Fraternal twins (DZ) share how many genes
50%
Identical twins (MZ) share how many genes
100%
Biological sibs share how many genes
50%
If genetic endowment is important, you would expect:
r’s of mz twins > r of dz twins
what is ‘r’
“r” is symbol for correlation;
Major Studies Comparing Extraversion of MZ and DZ Twins show how much heritability
about 50%
the big 5 is how heritable in general according to studies
50%
Can we explain MZ advantage environmentally?
Perhaps MZ twins are treated more similarly than DZ twins?
is there proof that MZ twins might act the same because they are raised the same
Shared environment only accounts for a small amount of variance.
Essentially, no– lots of separated twins with adoption and they still act the same
what is another personality variable (aside from the big 5)
locus of control
what is locus of control
belongs in level 2 (motivation, beliefs about how you can act in the world)
what is locus of control divided into
internal and external
what is internal locus of control
healthy end, believes if positive or negative actions happen to you it is part of your control
what is external locus of control
belief that things are random/chaotic! “even if I study I won’t do well at the exam….”
If 50% of the variation is genetic does that mean the remainder is the result of the environment, specifically parenting?
Not true, that would be too simplistic of an explanation;
2 different kings of environmental effect– shared and not shared
what is shared environmental effect
everything you share similar
influences that operate to make family members alike
what is not shared environmental effect
illnesses, accidents, birth order
influences that operate to make family members unalike
is the big 5 influenced by shared environment
Shared environment accounts for only a small amount of variance.
2-5% max
what is the ratio of genes:shared environment
10:1
“In teaching personality psychology for 25 years, my experience has been that students (and many colleagues) simply do not believe these results!”
is there an exception to the genes: shared environment
Exception: (Sandra Scarr)
Extreme Negative Environments
Abusive, neglectful
Is your birth order related to you Big 5 personality traits?
IQ is about 3 posts higher average
nothing about birth order is related to birth order
explain Life Events and Selective Impact on Big 5 traits (twin study)
Riese et al 2014
Tracked impact of stressful life events on levels of neuroticism in Finnish Twin Cohort (n = 20,000) over 6 years.
Stability of N high, r = .60.
but if looked at life events, if someone had difficult ones, it would increase their N for the twin that experienced the tough life events
But don’t genes and environment interact?
non-shared environment: peer groups
personality dictates what kind of group someone selects (it is not a random thing)
Why are siblings so different in their personality?
really only identical twins who are so similar
What role do genetics play in the development of personality traits?
large
What aspects of the environment are important in the development of personality traits?
not parenting,
parenting might have an influence on locus of control but that is not as fundamental as the big 5
Is your birth order related to you Big 5 personality traits?
no
