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

2. Key Biological Theorists
Charles Darwin
Ivan Pavlov
Hans Eysenck
Francis Galton

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

4. Natural Selection
Process by which certain adaptive characteristics emerge over generations

5. 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

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

7. 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

8. Introversion vs Extroversion
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

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

11. Sensation Seeking 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

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

16. 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
Try out this test to get the impact of right and left hemisphere operations

19. Top view of Brain genu of the corpus collosum head of caudate nucleus
putamen
globus pallidus
thalamus
tail of caudate nucleus
splenium of corpus callosum
amygdala
substantia nigra
Top view of Brain
genu of the corpus collosum
head of caudate nucleus
putamen
globus pallidus
thalamus
tail of caudate nucleus
splenium of corpus callosum
amygdala
substantia nigra

20. PET Scan of Brain of Adult with ADHD

21. PET Scans 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
PET Scans
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

24. 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
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

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

32. Neurotransmitters Impacted Too!
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 Impacted Too!
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

33. 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
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

34. Neurotransmitters
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

42. 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
Types of Neurotransmitters
Dopamine-dopaminergic system
Norepinephrine-noradrenergic system
Serotonin-serotonergic system
Control senses, thinking, perception, mood, attention, and behavior

43. Hans Eysenck-
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 system-brains emotional center regulates sex, fear & aggression
P – Psychoticism – linked to endocrine gland-especially which controls sex drive

44. Eysenck’s Types 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

45. Sir Francis Galton
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

46. Eugenics
Good Birth or Good Genes is the cause of peoples’ high intelligence and stable emotional well-being
Recommend forced sterilization of the poor

47. 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.

48. 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

49. Somatotypology-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

50. 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

51. 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

52. 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

53. 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

54. 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

55. 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