Transformation of Psychology in the 19th Century

1. Chapter 4: The Nineteenth-Century Transformation of Psychology A History of Psychology (3rd Edition) John G. Benjafield

2. Psychology in the Nineteenth Century • Beginning of nineteenth century: • Many believed psychology could never be a science • End of nineteenth century: • Possibility that psychology could be a scientific discipline seemed more plausible

3. J.F. Herbart (1776–1841) • Attempted to cast a psychological theory in purely mathematical terms • Interested both in what was above and below the threshold of consciousness • Below the threshold of consciousness = unconscious events that could become conscious

4. J.F. Herbart • Assumption that all mental life is the result of the action and interaction of elementary ideas • Elementary ideas: entirely simple concepts or sensations • Ex. red, sour

5. J.F. Herbart • Some ideas facilitate each other, while other ideas inhibit each other • Process of inhibition can be put into mathematical terms: • No matter how much B is inhibited by A, it will never be less than zero

6. J.F. Herbart • Apperceptive mass: the set of ideas that assimilates ideas consistent with it and rejects ideas inconsistent with it • All concepts strive against suppression • This striving for expression in consciousness is the source of the emotions • Herbart’s psychology is dynamic

7. Herbart and Educational Psychology • Goal of education: instill the values of the established order • Steps for instruction: 1. Preparation 2. Presentation 3. Association 4. Generalization • Fifth step added later: Application

8. Herbart’s Contributions to Psychology • Notion that ideas can move back and forth across a threshold of consciousness • Attempt to apply mathematics to psychology • Attempt to apply psychological ideas to education

9. G.T. Fechner (1801–1887) • Studied medicine at Leipzig, Germany • Moved to literary field • Studied physics • Became professor of physics at University of Leipzig • Responsible for creating an approach to psychology that was seen as truly scientific

10. Psychophysical Parallelism • Panpsychism: the notion that the mind permeates everything in the universe • Intimate relationship between mental and physical • Relationship is one of psychophysical parallelism: a strict parallelism between body and soul such that from one, properly understood, the other can be constructed

11. Psychophysics • Inner psychophysics: the study of the relationship between mind and brain • Outer psychophysics: the study of the connection between stimulus magnitudes and the intensity of the resulting sensations

12. Weber’s Law • Weber’s Law: the relation between a stimulus magnitude and the amount by which that magnitude must be changed in order for the subject to perceive a Just Noticeable Difference (JND) • Requires that we regard our basic experiences, or sensations, as quantifiable • Quantity objection: a refusal to accept this assumption of psychophyics

13. Fechner’s Psychophysical Methods • Method of just noticeable differences • Method of right and wrong cases • Method of average error

14. Experimental Aesthetics • Experimental aesthetics: psychology of beauty • Aesthetics from above: evaluate art according to standards derived from some theory of what art should be • Aesthetics from below: depends on obeservations of spectators’ responses to art in order to try to understand the effects that art has on people • Empirical

15. Hermann von Helmholtz (1821–1884) • One of the greatest scientists of the 19th century • Career marked by his ability to bring the fields of physiology, physics, and mathematics to bear on any one subject • Influenced by Johannes Müller • Advanced a theory of specific energy of nerves

16. Hermann von Helmholtz • All nerves operate in the same way and transmit impulses at the same speed • Different experiences arise when nerves connect different sense organs to different places in the brain

17. Helmholtz on Perception • Young-Helmholtz Theory of Colour Perception: the degree to which each cone in the eye is stimulated determines the colour we see • Red, green, and blue receptors • Also: Trichromatic Theory of Colour Perception • Place theory: nerves located at different places in the cochlea are responsible for the perception of different pitches

18. Unconscious Inference • Unconscious inference: we infer, on the basis of previous experience, that particular objects in the world have given rise to the images on our retinas. • The result of this process is the three-dimensional world we experience

19. Ewald Hering (1834–1918) • Formulated a competing theory to Helmholtz’s theory of colour perception • Opponent process theory of colour vision: • The visual system is based on three pairs of antagonistic processes • Light acts on each pair to yield one of its component colours but inhibit the other • The pairs are yellow-blue, red-green, and white-black

20. Christine Ladd-Franklin (1847–1930) • Trained for a PhD in logic and mathematics at Johns Hopkins University • Not awarded the degree because she was a woman • Unable to hold a regular university position for most of her career because she was married

21. Ladd-Franklin’s Theory of Colour Perception • Evolutionary-based theory • Stage 1: vision sensitive only to achromatic colours ranging from white to black • Rods represent the earliest stage of the development of vision • Stage 2: emergence of cones sensitive to yellow and blue • Stage 3: some of the cones sensitive to yellow undergo a further specialization to become cones sensitive to red and green • Evidence for her theory comes from the study of colour blindess • Studied people unable to see red and green but able to see yellow and blue • Law of progressions and pathologies: the last system to evolve is the first to show effects of degeneration

22. The Localization of Function • Localization of function controversy: controversy over the attempts to locate particular psychological functions in the cortex of the brain • Phrenology • Study of brain injuries

23. Phrenology • Franz Joseph Gall (1758–1828) and J.G. Spurzheim (1776–1832) • Believed the more highly developed a function, the larger it would be • The larger a function, the more it would protrude from the skull • Thus, one could divine a person’s strengths and weaknesses by examining the shape of skull • Phrenological chart: chart of the skull representing the locations of various psychological functions

24. The Study of Brain Injuries • Paul Broca (1824–1880) • Investigated the loss of the ability to express ideas by means of speech (Broca’s aphasia) • Autopsy of patient showed severe damage to a part of the left hemisphere (Broca’s area) • Karl Wenicke (1848–1905) • Studied 10 cases of patients who could speak but could not understand what was said to them (Wernicke’s aphasia) • Found lesions in the left hemisphere (Wenicke’s area)

25. Study of Brain Injuries • Studies of the relationship between the loss of psychological function and brain damage: • Can be a very suggestive source of evidence • Are seldom definitive or complete

26. Francis Galton (1822–1911) • Born in England • Cousin of Charles Darwin • One of the most versatile and prolific scholars in the history of psychology • Many of his opinions are still controversial

27. Hereditary Genius • Galton developed the hypothesis that ability and genius are hereditary • Galton’s Law: the two parents contribute one-half of the total heritage of the offspring, the four grandparents one-quarter, etc.

28. Eugenics • To Galton, the implication of his studies was that society should encourage selective breeding of humans • Eugenics • Eugenic movement became influential in the early twentieth century

29. Galton and Statistics • Normal distribution: a symmetrical distribution, with an equal number of events on the left as on the right • Regression towards the mean: occurs as a mathematical necessity whenever two variables are not perfectly correlated

30. Galton and Memory • Examined his own memory in great detail • Employed techniques that have developed into widely used experimental procedures • Autobiographical memories: memories of events in one’s life

31. Herbert Spencer (1820–1903) • 1852: coined the phrase ‘survival of the fittest’ • Evolutionary theory applied to the inorganic, organic, and super-organic (ie. societies) • Law of evolution: evolution is a process by which a system moves from an indefinite, incoherent homogeneity, to a definite coherent heterogeneity

32. Social Darwinism • Social Darwinism: individuals should be left to their own devices • (Ex. the state should not interfere with the evolutionary process) • Some successful American business people took up social Darwinism: • Ex. John D. Rockefeller, Andrew Carnegie