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The 19 th century Paving the Way for a New Science.

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1 The 19 th century Paving the Way for a New Science

2 Positivism Auguste Comte 1798 – 1857 Grandfather of sociology Comte that the only thing we can be sure of is that which is publicly observable – sense experiences that can be perceived by others  Positivism equates knowledge with empirical observations. He proposed that societies and disciplines pass through stages defined by the way members explain natural events.  First stage Theological, based on superstition and mysticism,  Second stage Metaphysical, based on unseen essences, principles, causes, and laws  Third stage Scientific, in which positive knowledge replaces superstition and metaphysics Critical period  Point of transition from one stage to the next, where one system of thought is supplanted by another

3 Positivism New sciences emerge from the principles of established ones and develop methods appropriate to its problems  Sociology compares cultures in various stages of evolution Dismissed psychology, the study of the mind, as ‘an idle fancy, and a dream, when it is not an absurdity’  However we can study phrenological psychology as well as the products of mental life (i.e. sociology)

4 Positivism Comte proposed a religion of humanity which was a utopian society based on scientific principles and beliefs  Saw science as a new type of religion enabled to solve our problems Humanity replaced God, scientists and philosophers would be the priests in this religion He also arranged sciences in a hierarchy from the first developed and most basic to the most recently developed and most comprehensive  The list: mathematics, astronomy, physics, chemistry, physiological biology, and sociology at the apex

5 Positivism Ernst Mach 1838 - 1916 Proposed a second brand of positivism, which differed from Comte’s positivism primarily in what type of data science could be certain about  Comte: physical events able to be experienced by any observer  Mach: can’t experience the world directly, only sensations or mental phenomenon The job of science is to describe the relationships of those sensations  Has to do with the psychology rather than the reality

6 Enter Evolution Early evolutionary ideas Early Greek ideas  Plato and Aristotle both had a form of evolutionary ideas but neither one truly believed in evolution Later Christian thought added its version of a divine creation By the 18th and early 19th century several prominent people were postulating a theory of evolution (including Darwin’s grandfather Erasmus)  What was missing from these early theories was a mechanism to account for the theory Jean Lamarck 1744-1829  The theory of inheritance of acquired characteristics stated that environmental changes during the lifetime of the organism resulted in structural changes in plants and animals and these changes would be passed on to the offspring, which in turn enhanced their chance for survival

7 Charles Darwin 1809-1882 The concept of evolution is a very old one and has progressed through the ages  Aristotle  Goethe  Comte Nature-as-enemy produces ‘fit specimens’ Darwin brings in the notion that evolution, or ‘progress’, is not only possible, but inevitable and mechanistic

8 Charles Darwin Influences The voyage of the Beagle – Darwin was hired as a naturalist/scientist for a 5-year expedition to collect scientific facts to support the Biblical account of the creation During the voyage he collected hundreds of specimens and made hundreds of observations He also read the book Principles of Geology (Lyell) that had the effect of starting Darwin thinking in terms of eons of time  Necessary for a theory of evolution to be viable, but not exactly consistent with the Biblical account

9 Charles Darwin With all of these observations his ideas of evolution were in their infancy The reading of Thomas Malthus’s Essay on the Principles of Population provided him with the mechanism/principle to complete the formulation of the theory  The essay proposed that food supply and populations size were kept in balance by events such as war, starvation, and disease In other words, we could increase the population indefinitely, but are kept in check by ‘opposing forces’ Darwin applied the Malthusian concepts to all living systems

10 Charles Darwin The theory of evolution There is a natural struggle for survival because there is an overabundance of offspring than can survive within a given environment Within a species there is variability, which produces vast individual differences in characteristics, some of these characteristics are more conducive to the organism’s survival within particular environmental conditions (environmental pressure) than others This struggle for survival results in the survival of the fittest  Therefore, a natural selection occurs Evolution, in other words, results from the natural selection (selection by environmental pressures) of those accidental variations among members of a species that prove to have survival value

11 Charles Darwin For Darwin, fitness was defined solely in terms of the organism’s ability to survive and produce offspring Darwin said nothing about progression toward a goal or perfection, evolution just happens due to natural environmental pressures His initial book, On the Origin of Species referred to humans very little but in The Descent of Man he makes his case for humans being a product of evolution

12 Charles Darwin Darwin’s Psychology  The Expression of the Emotions in Man and Animals Noted the similarities, in e.g. the expression of anger, across species  Helped lay the groundwork for comparative psychology The behavior and emotions expressed are the products of simpler ones from the past Psychological evolution is concomitant with structural and anatomical evolution

13 Charles Darwin Impact - the theory was revolutionary and its impact is still affecting the behavior of scientists and philosophers today in fundamental ways It changed the traditional view of human nature and the view of our place in the universe The theory has influenced all areas of psychology, and particularly played a significant role in the development of functionalism and subsequently behaviorism and of course, today’s evolutionary psychology

14 Herbert Spencer 1820-1903 Spencer applied his view of evolution to everything in the universe, including the human mind and societies Through evolution, differentiation occurs and systems become increasingly complex and move toward perfection In essence, evolution had a purpose which was to progress toward perfection

15 Herbert Spencer Actually thought well of the phrenology movement, and sought to tie the concept of localization of function to evolution  “Nevertheless, it seems to me that most physiologists have not sufficiently recognized the general truth of which Phrenology is an adumbration. Whoever calmly considers the question, cannot long resist the conviction that different parts of the cerebrum must, in some way or other, subserve different kinds of mental action. Localization of function is the law of all organization whatever; and it would be marvelous were there here an exception… Any other hypothesis seems to me, on the face of it, untenable” Accepted the Lamarkian notion of the inheritance of acquired characteristics

16 Herbert Spencer The Spencerian system Sensory systems project to specific regions of the brain Repeated stimulation results in a greater facility of neural transmission Prior experiences are chemically stored within the cerebral hemispheres The ‘subjective’ is the other side of the ‘objective’ Complexities of human neuroanatomical organization are to be understood as the evolved forms of a more primitive organization

17 Herbert Spencer He applied evolutionary theory to selection of behavior in what was called the Spencer-Bain Principle  He proposed that the probability of a behavior occurring in the future is a function of whether it is followed by a pleasurable event or a painful event Precursor to Thorndike’s Law of Effect and what Skinner would call selection of behavior by consequences Spencer went on to propose that these propensities for various behavioral responses could be passed on to offspring

18 Herbert Spencer Spencer applied the notion of survival of the fittest (he first coined the term and it was later used by Darwin) to societies and entities within societies  This is the concept of Social Darwinism  “If [individuals] are sufficiently complete [both physically and mentally] to live, they do live, and it is well they should live. If they are not sufficiently complete to live, they die, and it is best they should die” According to this idea, societies and entities within societies, for example businesses and companies, evolve and those, which are “more perfected”, survive and those, which are not do not survive This was compatible with the capitalist and individualistic philosophy in the United States at this time in history, where social Darwinism was accepted to a great extent

19 Francis Galton 1822-1911 First cheesy weatherman Cousin of Darwin, became interested in studying the inheritance of human abilities and individual differences Galton’s early research attempted to show that human abilities, including intelligence were primarily inherited In the course of his research he developed the first word-association test He was also among the first to study imagery

20 Francis Galton In his desire to measure the individual differences among humans he developed the “anthropometric laboratory” with which he collected data on more than 9000 humans The vast amounts of data he collected required Galton to device a way to analyze the data He initially looked at the data using scatter plots to observe the correlation between variables  Later, Karl Pearson developed the mathematical formulation for the correlation coefficient to give a mathematical expression of relationships between variables With the data he also observed a regression toward the mean  Data points on a particular variable will tend to cluster around the mean for that characteristic

21 Francis Galton His work on the heritability of characteristics produced the nature-nurture controversy, which is interested in how much of the variability we see in the population regarding a particular characteristic is due to heredity and how much is due to environmental factors.  This ‘controversy’ is still important today. Because Galton concluded from his research that there was a strong inheritance component to intelligence and other factors he proposed that the human population could be improved by selectively breeding humans for particular characteristics, particularly intelligence.  Eugenics!

22 Francis Galton Among the contributions of Galton are a list of firsts 1) The study of the nature-nurture question 2) The use of questionnaires in research 3) The use of word-association tests 4) Conduction of twin studies 5) The study of imagery 6) Development of correlational techniques

23 19 th Century Materialism

24 Bell-Magendie Law Charles Bell 1774-1842 Francois Magendie 1783-1855 Demonstrated that sensory nerves enter the dorsal roots of the spinal chord and motor nerves emerge from the ventral roots  This separated nerve physiology into sensory and motor functions Not a collaboration but independent discoverers, and in fact was an intensely controversial discovery as to who got it first

25 Bell-Magendie Law Significant because it demonstrated that specific mental functions are mediated by different anatomical structures  No longer possible to think of nerves as general conveyers of vibrations or spirits Sensory nerves carried impulses from sense receptors to the brain, motor nerves carried impulses from brain to muscles and glands  Provided clear anatomical evidence of the sort of arrangement required by Descartes regarding the reflex  This suggested separate sensory and motor regions in the brain Perhaps most important, it reinforced confidence in the experimental approach to the study of behavior

26 Johannes Muller 1801-1858 Doctrine of specific nerve energies  Actually anticipated by Bell Each sensory system is maximally sensitive to a specific type of stimulation but may be stimulated by other forms of energy  E.g. touching the eyeball produces a visual experience Demonstrated that each of the 5 types of sensory nerves results in a characteristic sensation  In other words, each nerve responds in its own characteristic way regardless of the stimulation which activated it The quality of experience is determined not by the object but the nerves responding to it  Back to the mystery of the thing-in-itself

27 Early work on brain functioning Phrenology Franz Gall (1758-1828) and localization of function Developed the first cohesive ideas about phrenology  The magnitude of one’s faculties (in the mind) could be determined by examining the bumps and depressions on one’s skull

28 Early work on brain functioning Johann Spurzheim (1776-1832) popularized the practice of phrenology with books and demonstrations of its uses Several phrenologists claimed that particular faculties can become stronger with practice A number of educators took this “mental muscle” approach by suggesting that practicing could make the faculties associated with a particular discipline stronger Some folks have bigger bumps than others  Phrenology eventually developed racial undertones

29 Early work on brain functioning Pierre Flourens (1794-1867) using the ablation method (destroying part of the brain and noting behavioral consequences) investigated localization of function in the brain  E.g. cerebrum function is willing, judging, remembering seeing etc., cerebellum the coordination of the movements of locomotion He also noticed that in some cases the function that was lost to an ablation was regained later Paul Broca (1824-1880) and Carl Wernicke (1848- 1905) using observations in the clinical setting were able to localize language and communication functions in the brain

30 Early work on brain functioning Work of Fritsch, Hirzig, and Ferrier – using electrical stimulation of brain neurons, they found: 1.That the cortex is not insensitive as previously thought 2.That when a certain area of the cortex is stimulated, muscular movements on the opposite side of the body are elicited, thus discovering the motor cortex.  What would turn out later to be the sensory cortex was also discovered 3.These findings and observations by other researchers extended the Bell-Magendie law to the brain

31 Alexander Bain 1818-1903 Bain’s goal was to describe the physiological correlates of mental and behavioral phenomena, and he relied on the new findings of the Bell-Magendie law, doctrine of specific nerve energies and the ‘science’ of phrenology For Bain the mind has three components – feelings, volition, and intellect Intellect is explained by the laws of association, primarily the law of contiguity which applies to sensations, ideas, actions, and feelings Contiguity supplemented by the law of frequency  The laws had their effect in neuronal changes in the nervous system

32 Alexander Bain Bain added two other laws of association.  Law of compound association – single ideas are not associated, rather an idea is usually associated with several other ideas through contiguity or similarity  Law of constructive association – the mind can rearrange memories of experiences into an almost infinite number of combinations, accounts for creativity Voluntary behavior is explained as follows:  When a need arises, spontaneous or random activity is produced  Some of those movements will produce approximate conditions necessary to satisfy the need, other movements will not  Activities which produce need satisfaction are remembered  When in similar situation again, the activities which previously produced need satisfaction will be performed  Precursor to Thorndike’s Law of Effect Bain and Spencer did much to lay the foundation for a science of psychology and successfully wedded it to biology It would be Wundt’s experimentation that would eventually solidify its place in the realm of science

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