Chapter 5: Biological Aspects of Personality

Evolutionary Psychology

Theoretical framework suggesting natural selection has led to certain genetically-based characteristics affecting personality and social behavior.

Natural selection

Process where certain characteristics increase the reproductive success of an organism, leading to greater survival of the species.

Heritability

A measure of the proportion of variability in a trait within a population that is associated with genetic variability.

Temperament

Stable individual differences in emotional reactivity, typically apparent early in life, influenced by nervous system responses.

Eysenck’s CNS Model of Temperament

Proposes that differences in central nervous system activity account for levels of introversion and extraversion in individuals.

Behavioral Activation System (BAS)

A system that regulates a person’s response to rewards and pleasurable stimuli.

Behavioral Inhibition System (BIS)

A system that orients a person to novel situations, responding to punishing or aversive stimuli.

Cloninger’s Tridimensional Model

A model proposing three biologically-based personality traits tied to specific neurotransmitter functions in the CNS.

Novelty Seeking

A tendency to become excited by novel stimuli and explore the environment, related to dopamine activity.

Harm Avoidance

Tendency to worry and feel tense, related to aversive stimuli and punishment signals, positively associated with serotonin.

Reward Dependence

A behavioral maintenance system characterized by persistence in actions that produce rewards, inversely related to norepinephrine.