1. 19th Century Precursors
Psychology 4006

2. Introduction
The knowledge of the renaissance was finally hitting the masses.
The industrial revolution made it so people had jobs, and kids would go to school.
You didn’t necessarily have the same job as your father.
The 19th Century was really a great upheaval in society.

3. The Species Problem The “mystery of mysteries”
What accounts for the large number, the diversity, the occasional disappearance, the existence of fossils, etc.?
Big problem for academics in the UK
they were also clergy
William Paley the argument from design
Elegant design requires a designer (i.e., God)

4. Early Evolutionary Ideas
Erasmus Darwin – evolution from a single “filament”
Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck
Chain of being
Inheritance of acquired characteristics

5. One of my Heroes Charles Darwin (1809-1882)
False starts medicine, clergy
Finds life’s work at Cambridge
Influence of Henslow (biology) and Sedgewick (geology)
Voyage of the Beagle
Contributions to geology
Supported Lyell’s “uniformitarian” views
Contributions to biology
Huge specimen collection
Galápagos episode
Finch varieties (not noticed at the time of his visit

6. If Aliens Ever Come To Earth….
Elements of the theory
Individual variation
Some variations “favorable”
Increase chances of surviving the struggle for existence
These variations “selected” by nature
i.e., natural selection

7. Reaction The Oxford debates Huxley ‘Darwin’s bulldog’
Scientific acceptance
The personalistic vs. naturalistic issue again
Evolution “in the air”
But Darwin a prime mover

8. Darwin and Psychology Functionalist thinking
Led to comparative psychology
Continuity and difference among species
Led to study of individual variation
Individual differences
Modern evocation
Evolutionary psychology

9. Comparative Psych, It’s What The Cool Kids Take
Darwin ‘Expressions of the Emotions in Man and Animals’ (1872)
Serviceable associated habits
Antithesis
Direct action of nervous system
Douglas Spalding ( )
Instinct
Argued against British Empiricist view
Imprinting
Critical periods

10. Individual Differences
Sir Francis Galton ( )
Numerous non-psychology contributions
Exploration, meteorology, fingerprinting
Desired to apply evolutionary thinking to the question of intelligence
Eminence rates
Hereditary Genius (1869)
Surveys and twin studies
Converged on conclusion that intelligence was inherited
Implications
Eugenics
Need for accurate measurements

11. Galton Anthropometric lab – Measurements based on Physical measures
Sensory/motor capacity
Related through “correlations”
Studying imagery
Misinterpreted his own data
Scientists showed more imagery than he realized
Studying association
Word association test
Hinted at unconscious

12. Johann Friedrich Herbart (1776-1841)
He took a psychological approach to educational problems.
He attempted to quantify phenomena in psychology.
studied apperception, mental operations more complex than sense perception
the goal of education was to build the apperceptive mass.
Education must also be moral education.

13. Psychophysics, Que-est-ce que c’est
Ernst Weber ( ) - Leipzig
interested in sensory processes other than vision and hearing
research on two-point thresholds
Mapping skin sensitivity
Weber’s Law
Weight-lifting studies
jnd = just noticeable difference between weights
jnd’s were proportional to the size of the smaller weight
jnd/S = k
If 30g and 33g are just noticeably different, then 60g and 63g will not be noticeably different (must be 60g and 66g)

14. No, really, actually psychology!
Gustav Fechner ( )
Systematic analysis of psychophysics
Relationship between physical stimulus and psychological experience of it
Elements of Psychophysics (1860)
Inspiration came 10 years before
Fechner Day  October 22
Methods for determining absolute and difference thresholds
Limits
Constant stimuli
Adjustment

15. Early ‘Neuroscience’ The Bell-Magendie Law
Posterior roots of spinal cord  control sensation
Anterior roots  control motor movement
The specific energies of nerves
credited to Johannes Müller
Two parts
We do not perceive the world directly, but rather the action of our nervous system
Nerves corresponding to different senses have different “specific energies”
2 different stimuli, one type of nerve, one type of sensation
1 stimulus, two different types of nerves, two types of sensation

16. Helmholtz Hermann Helmholtz (1821-1894)
(as an aside, did everyone just look super intense back then?)
Speed of the neural impulse
Relative slowness demonstrated that physical/chemical processes involved
the basis for the development of reaction time methods

17. Helmholtz Research on vision Trichromatic theory (Young-Helmholtz)
Receptors for three primary colors – red, green, blue/violet
Other colors involved combinations of receptors
Still accepted at the retinal level
Research on hearing
Resonance theory
Different frequencies detected by receptors in different locations on the cochlea

18. Localization of Brain Function
Franz Joseph Gall ( )
Proposed craniometry  later called phrenology
observed relations between head shape and individual’s personality or ability
Basic principles of phrenology
brain is the organ of the mind
mind composed of a number of “faculties”
Intellectual, affective (emotional), personality
each faculty located in a specific place on the cortex
Phrenology  First serious localization theory
strength of a faculty reflected in proportional brain size
skull reflects brain contour
Enables measurement of faculties by measuring skulls

20. Phrenology Problems with phrenology
Relied too much on anecdotal evidence
Avoided falsification
Apparent disproof explained away (combo of other faculties)
Popular in U.S.
Consistent with American values
Opportunity
Uniqueness
Application

21. Actual Real Localization of Brain Function
Case of Phineas Gage
Accident results in serious brain damage
changes in behavior lead to inferences about the affected portion of brain
For Gage severe frontal lobe damage altered rational control over emotions

22. Broca Case of “Tan” Paul Broca (1824-1880)
Some behavioral/emotional problem occurs
Correlated with brain damage upon autopsy
For Tan loss of productive speech (motor aphasia) led to labeling of “Broca’s area” in left hemisphere

23. Conclusions
Don’t ever underestimate the importance of evolutionary thinking to psychology
Now we see the importance not of philosophy but of biology