BIOLOGICAL ASPECTS OF PERSONALITY
Key Biological Theorists include
- Charles Darwin
- Ivan Pavlov
- Hans Eysenck 1916-1997
- Francis Galton
Evolutionary Personality Theory
- It is application of Darwin’s Theory of Evolution of natural selection
- It states that function of a survival characteristic evolves over time
- Belief that many of individual characteristics are “in our bones” in our genes
- Natural selection is a process by which certain adaptive characteristics emerge over generations
Survival of the Fittest
- Darwin’s concept that the fittest survive over time
- Misused to mean: weak creatures should not survive
- Pseudoscientific justification for the oppression of minorities
Social Darwinism
- Applying evolutionary theory in a crude way to society
- Not only individuals but societies and cultures naturally compete in survival of the fittest
- It was ok to subjugate those seen as inferior race or culture
Genetic Personality Types
Examples of Genetic Personality Types
- Angelman Syndrome – chromosome 15
- Friendly
- Oral driven
- Downs Syndrome - chromosome 21
- Friendly – easy to get along with
- Caring, Loving
- Approval seeking
Mediated effects of Biology
- Disease-Parkinson’s, ear, heart, lung, systemic, surgery
- Poisoning-mercury, lead, manganese
- Brain disease-Alzheimer’s, strokes, epilepsy, tumors
- Illegal drugs, LSD, cocaine, crack
Human Temperament:
Study of Temperaments is based on Work of Pavlov
- Human Temperament is defined as stable individual differences in emotional reactivity which remain stable as children mature
- Different nervous system responses to unpleasant stimuli
4 Basic Aspects of Temperament
- Social-Introversion-Extroversion- seek or avoid being with/in front people
- Emotionality-fearful, angry, mood swings vs relaxed, calm, placid, stable
- Activity-vigorous, always in motion vs passive, lethargic
- Impulsive-aggressive-bully vs peace maker, plans vs quick changes, cold vs conscientious & friendly
Work of Hans Eysenck
Hans Eysenck proposed 3 Type Theory –which is based on Biological Determinism. Basically it postulates Heredity in Everything
- E – Extraversion – linked to ascending reticular activating system (ARAS)-reticular formation of Brain Stem
- N – Neuroticism – linked to limbic system-brains emotional center regulates sex, fear & aggression
- P – Psychoticism – linked to endocrine gland-especially which controls sex drive
Eysenck’s Types
- Extraversion – introversion
- Neuroticism – stability
- Psychoticism – superego functioning
- People show degrees of all 3 types
- Encouraged Twin studies especially of identical twins who were adopted separately
Introversion vs Extroversion:
- This is also based on work of Hans Eysenck who ties this to central nervous system – Biologically based personality theory
- Extroverts – Low level of Brain arousal and seek stimulation
- Introverts – High level of Brain arousal shy away from over-stimulation
Work of Sir Francis Galton
- He Supposed that Upper Class Englishmen were a superior population
- Began the study of adoptive twins
- Began the “eugenics” movement
- Encouraged eminent families to have lots of children to improve the human blood lines
Eugenics
- Good Birth or Good Genes is the cause of peoples’ high intelligence and stable emotional well-being
- Recommend forced sterilization of the poor
Kin Selection
- Nieces and nephews of people with certain traits thought to be genetic based- homosexuality, schizophrenia, bipolar disorder – genetic tendency toward these conditions survives since nephews and nieces share some genetic makeup with uncle or aunt who has these traits.
Nervous System Arousal
- Stable people have well-modulated nervous systems
- Neurotic people have very reactive nervous systems
- Tests: EEG, Electrodermal measure (which reads brain activity)
Somatotypology
It was proposed by W. H. Sheldon 1942
- Three Body Types have influence on personality:
- Mesomorphs-muscular, large boned, athletic
- Ectomorphs- slender, bookworm
- Endomorphs- overweight, roly-poly, good natured
Sociobiology
- Scientific study of the influence of evolutionary biology on individual responses regarding social matters
- Focus: Analysis of human aggression, human courtship and raising young children
Attachment
- Close bond – develops shortly after birth between infant and caretaker(mother)
- Infant clings, gurgles, smiles to attract caregiver-so that caregiver will nurture the infant
- Attachment system insures survival of the of infant-ensures passing of mothers genes
- Evolutionary function for cuteness of infants
Human Genome Project
- The accomplished task of identifying the tens of thousands of genes in chromosomes
- Develop treatments for inherited diseases
- Movement towards Gene Therapy
- Potential threat: genetic engineering
Biological Determination
- Personality simply a matter of genes, brains, and hormones
- Behavior is determined by biological tendencies
- Minimizes the human potential for growth and change
Functional categorization of Central Nervous System:
The Brain
- Brain reaches its maximum number of synaptic connections and its greatest metabolic activity around age 3 or 4
Brain Hemispheric Hypothesis
- Left side of Brain-Role in Positive Emotions-Creative side of Brain
- Right side of Brain-Role in Negative Emotions-Methodological, systematic side of Brain
Messages from Brain Travel by Nervous System
- The Central Nervous System is the Communications Highway of the body
- Brings help to the body based on the messages it screens from the environment
Neurotransmitters
- Brain = Billions of Brain Cells-Neurons
- Neurons transmit information – electrical conduction within nerve cells & between nerve cells
- Message once carried through body cell (Axon) crosses space –Synapse to receiving cell
- Tip of Axon-tiny sacs contain neurotransmitter chemicals which are automatically released by sending nerve cell
- Neurotransmitter chemicals excite receiving cell causing cell to fire to send message through its own body-Axon to next receiving cell
- Once message received neurotransmitter is deactivated and taken up from synapse and stored in sacs so as not to cause repeated firing of the receiving cell
Types of Neurotransmitters
- Dopamine-dopaminergic system
- Norepinephrine-noradrenergic system
- Serotonin-serotonergic system
- Control senses, thinking, perception, mood, attention, and behavior
- Unfortunately at this time we can not measure amount for baseline therapeutic levels