survival。
5。 Emphasis on Change。 Before evolutionary theory； the monly held view was that the earth and its
inhabitants were immutable and static。 Darwin’s portrayal of nature is dynamic； mutable； and
interacting。
Darwin’s ideas influenced many psychologists； including Freud； Watson； Skinner； and James。 The most
apparent legacy from Darwin to Freud’s theory was the idea of the continuity of animals and humans。
Freud thought humans were driven by the same instincts that motivate other animals—instincts to survive
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and reproduce。 According to Freud； people have no inherently higher nature than do animals； and
whatever in humans may be higher （sympathy； altruism； unselfishness） is a product of the processes of
repression and reasoning。 In Freud’s perspective； the dominant force in the structure of personality is the id
（the representation of the instincts for survival and reproduction）； but humans develop other aspects of
personality to control these instincts in order to adapt to munal lifestyles。 munal living is
important in terms of adaptive behavior for humans because humans are rather weak creatures pared to
the large predators。
The idea of continuity between animals and humans also influenced the behaviorist theories of Watson and
Skinner。 Watson began his career as an animal psychologist believing； as later did Skinner； that the basic
principles of behavior can be discovered by studying the behavior of animals。 Though behaviorists do not
deny individual differences in genetic endowment； they do tend to place greater emphasis on
environmental determinants of behavior。 Skinner emphasized learning rather than innate factors as being
the antecedent of behavior； believing that through a process of trial and error； organisms learn which
behaviors lead to reinforcement…things that ensure survival and reproduction…and which behaviors are
futile； and are followed by loss or punishment。 Thus； according to behaviorists； learning is our primary tool
for adaptation； and it is the environment that shapes behavior； rather than “mind” or “consciousness”
within the organism。
Behaviorism also emphasizes change。 Both Watson and Skinner suggested that a utopian society could be
built by imposing proper control on environmental conditions。 Emphasis on change is one of the hallmarks
of our society； we are convinced that we can be better； thinner； smarter； richer； and happier。 Psychologists
have been in the forefront in convincing us that change is possible； though not necessarily easy。
The idea of adaptation to the environment was the central Darwinian theme in the functionalism of William
James and the originators of the functionalist approach。 Human behavior （James used the term “habits”）
was considered in terms of how it served the goal of adaptation。 Like the behaviorists； the functionalists
saw learning as the primary mechanism for human adaptation and survival。
A precursor of functionalism was the British intellectual giant； Sir Francis Galton。 Using Darwin’s theory；
Galton developed a keen interest in individual differences and strived to devise ways to measure these
differences。 American psychologists eagerly adopted his ideas； with their emphasis on individualism。
Psychological testing developed from this facet of functionalism and continues to be an active area in
American psychology。 We have developed psychological tests to measure almost any trait you can imagine。
Ironically； the founder of psychology as a science； Wilhelm Wundt； was not significantly influenced by
Darwin’s theory； and when Wundt’s branch of psychology； structuralism； migrated to America； it was
unable to adapt and survive。
BIOGRAPHICAL PROFILES
Rene Descartes （1596—1650）
Born of wealthy parents in La Haye； France； Descartes was one of the most influential thinkers of the
Renaissance。 He contributed to mathematics； philosophy； psychology； and physiology。 Descartes； a very
private man； enjoyed solitude and was iconoclastic。 While enrolled at a Jesuit school； he convinced the
school authorities to allow him to sleep until 11 A。M。； because he did his best thinking while in bed。
Perhaps because of this individualistic nature； Descartes began to doubt all that he had learned in school。
This skepticism soon spread to all areas of his life。 Descartes doubted everything。 Of one thing； however；
Descartes had no doubt： that he was doubting。 This led to his famous conclusion； “Cogito； ergo sum。” “I
think； therefore I am”； which suggests that all that is certain concerning the human condition is that each of
us exists。 Descartes also made significant contributions to physiology。 He believed that what distinguished
living from nonliving material was “animal spirits”。 Animal spirits； according to Descartes； gave humans
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CHAPTER3： THE BIOLOGICAL BASES OF BEHAVIOR
their ability to move and worked mechanically； like hydraulics。 Although his notion of animal spirits has
been shown incorrect； his study of both animals and humans paved the way for future discoveries。
Descartes also addressed the mind—body problem。 He thought that there was a physical body that could be
studied scientifically and that there was a mind that was not physical and that could not be studied
scientifically。 He felt that the mind and body interacted in the pineal gland； which sits at the center of the
base of the brain。 His position was thus dualistic and interactionist。
Because of interference by the Catholic Church and increased demands on his time because of his growing
fame； Descartes moved to Sweden in 1650 to tutor Queen Christina。 Unfortunately for humanity； Queen
Christina insisted on being tutored at 5 A。M。； well before Descartes’ 11 A。M。 wake…up time。 Within six
months of his arrival in Sweden； Descartes contracted pneumonia and died。
Paul Broca （1824—1880）
Born in Sainte…Foy…la…Grand； France； Broca was the only son of a physician； and followed his father’s lead；
being professor of surgery and anthropology in Paris in 1861。 During an autopsy on a patient who had
suffered from severe speech deficits； Broca discovered a lesion in the left frontal lobe。 This discovery was the
first evidence supporting Franz Gall’s notion of localization of brain function； a concept that is generally
viewed as accurate by current standards。
Broca was also responsible for developing the early science of craniometry； the measurement of the skull；
and the anthropological study of the prehistoric practice of trephining； in which small holes were made in
the skull of presumably mentally ill individuals in an attempt to allow demons to escape。 He was elected to
the French Senate in 1879 and his radical political views included the remendation that public high
schools open their doors to females。
Franz Gall （1758—1828）
Gall was born in Baden； Germany； but settled in Vienna as a physician。 He was a distinguished anatomist；
responsible for much of our early understanding of the nervous system； particularly the distinction between
the function of the white （myelinated） and gray （nonmyelinated） matter of the brain。 Along with his student；
Johann Spurzheim； Gall promoted the science of phrenology； in which a person’s character； and emotional
and intellectual dispositions could be inferred from an assessment of the various bumps and contours of the
head。 Although long since discredited as legitimate science； phrenology was extremely popular in its day。
（Darwin was nearly kept off the HMS Beagle because of the shape of his nose。） Nearly 30 phrenological
societies were in existence in England in 1832； and a number of professional periodicals concerning
phrenology flourished curing the mid…1800s。
Gregor Mendel （1822—1884）
Born in Heizendorf； Austria； Mendel’s father was a peasant； his mother a gardener。 After studying
philosophy at the University of Olmutz； Mendel entered the Augustinian monastery； where many of his
teachers also taught science and philosophy at the Gymnasium or Philosophical Institute。 Mendel was put
in charge of the experimental garden； where he began the studies that would e to be identified as the
founding of the science of genetics。 Conducting impressively systematic and thorough experiments of
hybridization of peas； Mendel accumulated evidence contradicting the current theory that inheritance was
a “blending” or bining process。
Mendel’s research was first presented at a scientific meeting in 1865 and in published form in 1866； but
went unnoticed。 In 1900； however； three separate scientists reported similar findings； despite having been
ignorant of Mendel’s work。
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PSYCHOLOGY AND LIFE
Roger Sperry （1913—1994）
Sperry obtained his M。A。 in psychology at Oberlin College； followed by a Ph。D。 in zoology from the
University of Chicago in 1941。 He conducted postdoctoral research under Karl Lashley at Harvard and at
the Yerkes Primate Center。 His early research challenged the traditional notion that nerves from sense
organs attach to brain areas in nonspecific ways。 Later； he and his students advanced the psychological
study of split…brain patients by developing laboratory tasks that allowed for precise assessment of the
frequently subtle impairments experienced by recipients of the radical operation。 In 1981； he was awarded
the Nobel Prize in physiology； primarily for his pioneering work during the 1960s on split…brain
phenomena。 Sperry wrote later about the mind…body relationship and the ethical implications of modern
research on brain physiology and behavior。
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TIMELINE
Yea Event
r
1662 Rene Descartes； a French philosopher—mathematician； published Trait de L’homme； introducing
the idea of reflexive behavior。
1687 Isaac Newton published Principia。
1739 David Hume published Treatise on Human Nature。
1831 Charles Darwin set sail on the five…year voyage of the HMS Beagle
18611865
The American Civil War was fought。
1865 Gergor Mendel reported his findings on genetic transmission of traits in garden peas。
1870 Gustav Frits