Lecture 7

Question 1

How many items does the gold standard big 5 test have?

Answer 1

220

Question 2

Openness to xp

Answer 2

High O people are complex, artistic original and imaginative

Low O ppl are down to earth, conventional and have narrow interests

O is more about thinking styles

Question 3

Heritability of height

Answer 3

90%

Question 4

Prov vs brother on trats

Answer 4

Richard         Roland
N      +                   -
E       -                   +
O      -                    +
A       +                   -
C       -                   +

Question 5

Temperament and personality traits

Answer 5

Young, 6 month old kids show differences in temperament

Easy vs difficult pertains to how easy they are to socialize. Often called “active” euphemistically

Question 6

Rochard and roland stories

Answer 6

Roland jumped out of play pen and locked mother in the closet then ran outside and shouted to his fried that he was free. Mom beat him :(

Richard could be left outside with a radio for hours in a playpen and was fine. But one day screamed cos a turtle was there. Mom explained turtle and afterwards was never scared of them.

Roland devil, Richard angel

Question 7

Twins and heritability basics

Answer 7

MZ twins have about 100% the same genes.
DZ twins have 50.
If r is higher for MZ than DZ, you might suspect a genetic link.

Question 8

MZ vs DZ for big 5 r

Answer 8

MZ = 50% across all traits

Sweden, USA, Canada, Germany all done for E

Question 9

Adoption studies show

Answer 9

It is genes and not similar environments/being treated the same.

Swedish twin study shows this for all big 5

Shared environment only accounts for a very small amount of variance.

There are also lots of similarities for MZ twins separated at birth (eg partners and habits).

Question 10

Locus of control

Answer 10

Is the amount to which you think you can control your life. 28 items.

In this case, MZ are only similar if raised together. As a result, this is more environmental.

Question 11

If 50% genes, is the rest parenting?

Answer 11

No. the Swedish study shows only 3% for MZ and 4% for DZ more similar if raised together. Hence the shared environment part of peoples upbringing really makes little difference.

It is 3-5% of the variance.

Question 12

Gene and environment variance

Answer 12

50% gene
5% shared
20% margin for error
leaves 25% for non-shared environment

Genes:shared environment (such as parenting)
10:1

Question 13

How much does birth order affect your big 5 traits?

And IQ?

Answer 13

Jefferson, Hebst & McRae, 1998
Large, representative study of 10000 adults
Big 5 traits
Controlled for SES, number of siblings, gender

It does not.

Another larger study in 2017 - same result

There is +3 iq for first born, + 1.5 for second
After than nothing

Question 14

Stressful life events and big 5

Answer 14

Riese et al, 2014
Tracked impact of a stressful life event on levels of N \
SLEs moderately increase N.
Exposure affected MZ twins distinctly, only the affected twin changed (so not a common factor)

Eg

Profs dad had TB
First two years of life, Roland lived alone with mom. 
Dad came back
Richard born after dad back
Maybe why Roland was the devil

Question 15

Abuse

Answer 15

Increases N and drops E

The only real way a parent can change big 5 personality traits.

Question 16

Anrisocial friends and peersonality

Answer 16

When kids fall in with a wrong crowd, possibly because the kids choose their friends based on their big 5.

Prof and bro had two siblings. Bros friend well adjusted, profs friend gang. Prof felt sorry but in reality, probs DNA.