What parts of my personality are set at birth?

Question 1

Longitudinal design

Answer 1

• individual interviewed repeatedly
• compare responses
• within individual change
• hard to retain participants (also they could die or refuse)

Question 2

Lewis Terman- Longevity project

Answer 2

-longitudinal study of intelligence and achievement

offered participants incentives so criticized for this

Question 3

(continuity) homotypic

Answer 3

• responses to the same instrument at different time points
• structural continuity
• differential/rank-order continuity
• absolute/mean-level continuity

Question 4

Structural continuity

Answer 4

• correlation between terms

- are the elements the same?

Question 5

differential/rank order continuity

Answer 5

-is the score likely to stay the same relative to the rest of the group (will high stay high?)

Question 6

absolute/mean-level continuity

Answer 6

-are you likely to get the same score again?

Question 7

Julian Morizot

-continuity and change in personality traits from adolescence to midlife

Answer 7

-“representative” and adjudicated boys
-structural continuity: disinhibition, negative emotionality, extraversion/positive emotionality
(elements of personality held across ages and samples)
-rank order continuity: gets stronger
-mean-level:
-all decrease with age

Question 8

(continuity) Heterotypic

Answer 8

responses to different instruments (but related construct) at different time points
-e.g. measures for kids (you have to adapt the measures for kids)

Question 9

Moffitt and Caspi (2000)

Answer 9

• Dunedin, NZ (all of the kids)
• assessed age 3-21
• minimal attrition (97% retention)
• age 3:
  
  • well-adjusted, undercontrolled, inhibited, confident, reserved
• age 18: the category of age 3 related to how participants describe themselves at age 18
• age 21: informant report, still see differences measured at age 3, also self-report and life-outcome, still related

Question 10

childhood self-control compared to life outcomes

Answer 10

• higher self-control as child
  
  • less likely to have adult health problems, financial struggles/problesm, convictions, single parent
  • more likely to have higher socioeconomic status

Question 11

Robert and DelVecchio (2010)

-meta analysis from childhood to age 70

Answer 11

• greater differential continuity with older samples when measured at shorter intervals
• when you are older, you are more selective with your environments, you choose people that lead to stability (so more likely to be same rank relative to others when you are older)

Question 12

Limitations of longitudinal design

Answer 12

• select samples
• significant attrition
• time, energy, resources
• confounding of age and cohort (are changes due to cultural/societal changes?)
• assumption of comparability across instruments
• reactivity to study

Question 13

Strengths of longitudinal design

Answer 13

• follow individuals over time

- examine individual change

Question 14

Francis Galton

Answer 14

• thought genetics made his family smart

- interested in cross-generational continuity within the family

Question 15

Equation for phenotype

Answer 15

influence of genes + influence of environment + interaction of genes and environment

Question 16

Genes/heritability

Answer 16

• proportion of observed phenotypic variance that can be explained by common genetic factors
• genes influence personality by shaping biological functioning
• behaviors shaped by functioning of many genes
• characteristic that is linked to genes can be altered by the environment

Question 17

environment

Answer 17

• all influences other than genetic inheritance
• shared: factors common to members of the same family making them similar (SES, neighborhood, culture)
• nonshared: factors not common to members of the same family making them different

Question 18

Monozygotic twins

Answer 18

-share 100 percent of genes

Question 19

dizygotic twins

Answer 19

-share 50% of genes

Question 20

Heritability coefficient

Answer 20

difference between differences within MZ and DZ twins
= (MZ difference - DZ difference)*2
= (100% shared genes + shared environment) - (50% shared genes + shared environment) *
= 50% shared genes * 2

Question 21

what have twin studies shown about personality?

Answer 21

• MZ more similar than DZ
• Extraversion = 60% heritability
• neuroticism = 50% heritability
• agreeableness, openness, conscientiousness = 40%
• moderate genetic influence found with peer reports
  
  • extraversion : 45% of variance in self-report is due to genes, only 20% of variance in peer report

Question 22

Criticism of twin studies

Answer 22

• not good measure of shared and non-shared environmental factors
• difficult to distinguish between shared genes versus shared environments

Question 23

MZ and DZ twins reared apart

Answer 23

• personality similarities can’t be due to shared environment
• heritability = 50% shared genes * 2
• still come up with same 40% heritability statistic
• shared environmental influnces may be due to shared heredity
• shared environmental influences personality less than shared heredity

Question 24

Limitations of behvioral genetic studies

Answer 24

• findings from twin/ adoption studies only tell us about those samples
• influenes of environment not measured
• no consideration of trends or common sociocultural factors
• common family enviornments can lead to different behaviors
• don’t know the mechanism by which genetic predispositions to certain personality traits are expressed