Biological factors in personality

n Genetic component

n Biological causes of personality

n disease

n drugs

n Biological correlates

n physiological arousal

n neurochemical changes

Why people react to biological theories

· Threaten notions of free will

· Suggest genetic/biological engineering of personality

· Medications as sole/best intervention

· “bad seed” notions of undesirable behavior

Determining genetic contributions

n Twin studies

n correspondence in MZ v. DZ twins

n MZ treated more similarly

n Adoption studies

n compare similarities to bio. & adopt. parents

n Twin/adoption studies

Hans Eysenck

n Three factors of personality

n extroversion-introversion

n neuroticism

n psychoticism

n proposed extraverts were underaroused

n proposed personality 2/3 genetically determined

Buss-Plomin temperament model

n temperament - style in which a response is made

n three temperament dimensions:

n activity

n emotionality

n sociability

n adult personality - interaction between temperament and environment

Kagan’s inhibited-uninhibited
children

n responding to novel situations with increased arousal

n predicts later behavior

n “An infant’s temperament renders some outcomes very likely, some moderately likely, and some unlikely - although not impossible, depending on experience”

Evolutionary Personality Theory

n Natural selection

n Anxiety

n survival

n social inclusion

Brain Activity and Mood

n Electroencephalograph (EEG)

n cerebral asymmetry

n left activation - positive mood

n right activation - negative mood

n support

n infant studies

n individual difference - differential reactivity

n depression