Biological Aspects of Personality Theories of Personality Prepared

Biological Aspects of Personality Theories of Personality Prepared by: Jim Messina, Ph. D.

Key Biological Theorists n n Charles Darwin Ivan Pavlov Hans Eysenck 1916 -1997 Francis Galton

Evolutionary Personality Theory Application of Darwin’s Theory of Evolution n Function of a survival characteristic evolves over time n Belief that many of individual characteristics are “in our bones” in our genes n

Natural Selection n Process by which certain adaptive characteristics emerge over generations

Examples of Genetic Personality Types n Angelman Syndrome – chromosome 15 n n n Friendly Oral driven Downs Syndrome - chromosome 21 n Friendly – easy to get along with n Caring, Loving n Approval seeking

Study of Temperaments-Based on Work of Pavlov n n Temperament: stable individual differences in emotional reactivity which remain stable as children mature Different nervous system responses to unpleasant stimuli

4 Basic Aspects of Temperament n n 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

Introversion vs Extroversion n Hans Eysenck – 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

Nervous System Arousal n Stable people-well-modulated nervous systems n Neurotic people-very reactive nervous systems n Tests: EEG, Electrodermal measure (lie detector)

Sensation Seeking n n n Seek new challenge or new high Seek highly stimulating activities Attracted to unknown Low level of natural (internal biological) activation –seek arousal from environment Left and right side of Brain

The Brain n Brain reaches its maximum number of synaptic connections and its greatest metabolic activity around age 3 or 4

Brain Hemispheric Hypothesis n n n 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 Try out this test to get the impact of right and left hemisphere operations

Top view of Brain 1. 2. 3. 4. 5. 6. 7. 8. 9. genu of the corpus collosum head of caudate nucleus putamen globus pallidus thalamus tail of caudate nucleus splenium of corpus callosum amygdala substantia nigra

PET Scan of Brain of Adult with ADHD

PET Scans n n Demonstrates metabolism of glucose in brain under arousal Brain on left is normal adult brain under arousal Brain on right is Brain of Adult with ADHD – frontal lobe of brain most involved in adults with ADHD

Messages from Brain Travel by Nervous System n n 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

Neurons where the messages are delivered! n Bio-chemical electrical impulses create a cascade of effects based on the message sent to various organ receptors of the body

Neurotransmitters Impacted Too! n n Not only are there physiological changes but there is altering of neurotransmitters based on messages from brain Absence or overabundance can create whole new set of consequences

Neurotransmitters n n n Brain = Billions of Brain Cells-Neurons transmit information – electrical conduction within nerve cells & between nerve cells Message once carried through body cell (Axon) crosses space –Synapse to receiving cell

Neurotransmitters n n n 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 n n n 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

Hans Eysenckn n 3 Type Theory –Biological Determinism. Heredity in Everything E – Extraversion – linked to ascending reticular activating system (ARAS)-reticular formation of Brain Stem N – Neuroticism – linked to limbic systembrains emotional center regulates sex, fear & aggression P – Psychoticism – linked to endocrine glandespecially which controls sex drive

Eysenck’s Types n n n E-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

Sir Francis Galton n n Supposition 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 n n 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 n 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.

Mediated effects of Biology n n Disease-Parkinson’s, ear, heart, lung, systemic, surgery Poisoning-mercury, lead, manganese Brain disease-Alzheimer’s, strokes, epilepsy, tumors Illegal drugs, LSD, cocaine, crack

Somatotypology-W. H. Sheldon, 1942 n n Three Body Types have influence on personality: Mesomorphs-muscular, large boned, athletic Ectomorphs- slender, bookworm Endomorphs- overweight, roly-poly, good natured

Survival of the Fittest n n n 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 n n n 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

Sociobiology n n 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 n n 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 n n 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 n Personality simply a matter of genes, brains, and hormones Behavior is determined by biological tendencies Minimizes the human potential for growth and change