1. BIOLOGICAL PSYCHOLOGY
NATURE VS. NURTURE

2. Gordon Allport Founder of the Trait Theory
Predispositions to respond, in a same or similar manner, to different stimuli
After meeting Freud, Allport felt there was too much emphasis on inner drives
Gordon Allport

3. Trait Theories of Personality
Personalities described by main characteristics (traits)
Traits (honesty, laziness, ambition, outgoing) thought to be stable throughout life

4. Key Ideas of Trait Theory
We are psychophysical beings
Mind and body function together
Personality develops from both mental and biological influence
Each person is unique
Everything is a characteristic of us and no one else
Heredity (genetics) provides “raw materials”
Environment shapes, expands, or limits heredity (raw materials)

5. Key Ideas of Trait Theory
In other words: individual combination of genes (except for identical twins) + the environment = personality
Two personalities
Childhood (more biological)
Adulthood (more environmental)
Childhood personality does not determine adult personality!

6. Other Trait Theorists

7. Hans Eyesenck Dimensions of personality
Extraversion vs. introversion (E)
Neuroticisms vs. emotional stability (N)
Psychoticism vs. impulse control (P)
Predisposed to each
Collectively makes up personality
Hans Eyesenck

8. Hans Eyesenck Extraversion vs. introversion (E) Extraverts Introverts
Lower level of cortical (brain) arousal
Seeks stimulation
Introverts
Higher level of cortical arousal
Shies away from stimuli
Hans Eyesenck

9. Hans Eyesenck Neurotic vs. emotional stability (N) Neurotic
Greater brain activity in sympathetic branch of autonomic nervous system
Alarm system – “fight, flight, or freeze”
Overreacts to even mild stress
Emotional stability
More subdued responses
More “level headed”
Hans Eyesenck

10. Hans Eyesenck Psychoticism vs. Impulse control (P) Psychoticism
Aggressive
Anti-social
Tough minded
Cold
Ego-centric
Cruel, hostile, insensitive
Men tend to score higher (hormonal)
Impulse control
Can channel aggression into appropriate activity
Hans Eyesenck

11. Hans Eyesenck Heredity plays greater role than environment
Descriptors of E
Sociable, lively, active, assertive, sensation seeking, carefree, dominant, venturesome
Descriptors of N
Anxious, depressed, guilt feelings, low self-esteem, tense, irrational, shy, moody
Descriptors of P
Aggressive, cold, egocentric, impersonal, impulsive, anti-social, creative, tough- minded
Hans Eyesenck

12. Robert McCrae and Paul Costa
“Big Five” factors of personality
Stability
Extraversion
Openness
Agreeableness
Conscientiousness

13. Stability (calm or anxious, secure or insecure, self-satisfied or self-pitying)
Extraversion (sociable or retiring, fun-loving or sober, affectionate or reserved)
Openness (imaginative or practical, variety or routine, independent or conforming)
Agreeableness (soft-hearted or ruthless, trusting or suspicious, helpful or uncooperative)
Conscientiousness (organized or disorganized, careful or careless, disciplined or impulsive)
The Big Five

14. The Big Five According to Big Five trait theory:
Traits are stable over time
Can be attributed to genetics
Describes personality equally across different cultures
Predicts other attributes
The Big Five

15. Correlations with the Big Five: Which behaviors correlate?
Protested injustice
- Emotionally stable, open
Fell in love at first sight
- Extraverted
Have not been in therapy
- Emotionally stable
Been in therapy
- Open
Thrown a large party
Kept a diary
Listen to music by self in dark

16. Correlations with the Big Five: Which behaviors correlate?
Read fewer than 12 books per year
- Extraverted
Never cheated on a test
- Conscientious
Never pulled all-nighter to finish assignment
Not likely to become addicted to Internet
-Extraverted
Dated a person of a different race
- Open
Written a poem spontaneously

17. Arnold Buss and Robert Plomin
Temperament
Building blocks of personality
Everyone has levels of all three
Primarily biological; can be adapted by environment

18. Arnold Buss and Robert Plomin
First Temperament
Emotionality
Level of excitability for unpleasant feelings
Sensitive to unemotional any emotion
Arnold Buss and Robert Plomin

19. Arnold Buss and Robert Plomin
Second Temperament
Activity
Physical energy and vigor
Constant unmoving movement
Arnold Buss and Robert Plomin

20. Arnold Buss and Robert Plomin
Third Temperament
Sociability
Preference for contact/interaction with others
Want to be Don’t like to be around others around others
Arnold Buss and Robert Plomin

21. Reflection: Looking at the Big Five and Three Temperaments, which ones do you see having the greatest impact on your life?
Assessing Our Traits

22. Untangling Nature and Nurture
Behavior Genetics: the study of the interaction of genes and environment on behavior

23. Nature vs. Nurture “Nature” = role genes have on a trait
“Nurture” = role life experience has on trait
Eysneck, McCrae and Costa, and Buss and Plomin all used twin studies in research
Nature vs. Nurture

24. Biological Theories of Personality
What % of the variation in a population is attributable to genes? - heritability
Not sure; BUT temperaments do seem to be stable from infants to old age.

25. Percentage of trait variation in a group that can be attributed to genetic differences (can be inherited)
In other words, what role do genetics play?
0% means genes play no role
100% means genes play entire role
Depends on the population
Heritability

26. Heritability Sara is very outgoing and agreeable
Suzy is timid and non-conforming
If this pair of IDENTICAL twins is my population, what percent of the personality differences is attributable to genetic differences between them?
The heritability is 0%.

27. Joe and Hank are not related
Joe and Hank are not related. At birth, both were placed in identical environments that were maintained identical until they were 10 years old.
At 10, Hank is withdrawn and shy.
At 10, Joe is outgoing and friendly.
In this (very small) population, what is the heritability of their personality traits? In other words, what percentage of the difference is attributable to genes?
Heritability
100%

28. How heritable is that trait?
Trait Population Heritability
Creativity adolescents 25%
Extraversion adults %
Autism general %
Depression general %
Sleep quality general 35%
TV viewing 3-5 year olds %
Religious beliefs general 0%
Religious conservatism women 40%
Divorce general 55%
Height women 92%
How heritable is that trait?
The Stanton Peele Addiction Website

29. Twin Studies Identical Twins vs. Fraternal Twins
Same genes, Different genes,
Same environment Same environment
Therefore, greater differences between the two groups indicate greater heritability (“Nature”). The trait might appear to have a large genetic component.

30. Twin Studies Criticism:
Do fraternal twins really have equally similar environments to identical twins? Differences in looks or inborn temperament may cause people to treat you differently.
Identical twins may share a placenta but fraternal twins do not. Thus, we can’t eliminate prenatal environments as the cause of the differences between the two groups.

31. Twin Studies
Identical Twins Reared Together v. Identical Twins Reared Apart
Same genes, Same genes,
Same environment Different environment
Greater difference between these two groups indicates greater role of the environment (“nurture”).

32. Twin Studies Criticisms:
Adoption agencies try to place twins in similar families so the variation in environment may be small, and
There is a very limited sample.

33. Adoption Studies Is child more like adoptive parents…
…or biological parents?
Adoption Studies
Adoptive Parents - Nurture
Biological Parents - Nature

34. Adoption Studies
Note: Two related siblings that grow up in the same family are strikingly different in personality (as I’m sure many of you can attest to).

35. Examples of theories? Nature? Nurture? Both? Twins?
Genetic engineering?
Examples of theories?

36. What is your opinion of the nature vs. nurture theory of psychology
What is your opinion of the nature vs. nurture theory of psychology? In other words, do you believe nature is dominant, nurture is dominant, or it’s a combination of both?
Please explain your answer!
Reflection