Aristotle
(384 -322 BC)
“There’s nothing in the intellect that wasn’t
previously in the senses”
Suggested basic principles of memory, as laws of
association:
– Contiguity in space or time
– Similarity
– Contrast (associations of opposites)
Socrates pointing to the Real world, moments
before his death by hemlock in 399 BC.
Galileo (1564-1642)
• Law of falling bodies
• Evidence for Copernicus’
heliocentric system (jailed
for this)
• No, planets don’t have
volition – they are moved
by external forces
The Reflex Arc
Descartes
(1596-1650)
Rene
Descartes
(1596-1650)
Luigi Galvani (1737-1798)
Muscle
contractions are
driven by
electrical impulses
The
Galapagos
Islands
Darwin (1809-1882)
Theory of Evolution by Natural Selection
• Crucial elements of theory:
– Variation among members of species
– Life is a battle for limited resources; the fittest
survive
– Mechanism of transmission to offspring
Homologous Structures: features that are
structurally similar because of common
ancestry.
Georges Romanes
Animal Intelligence (1888)
Relied heavily on anecdotes to build his
uncritical views on animal intelligence.
1848-1894
Occam’s Razor
The simplest explanation is the best
Morgan’s Canon of Parsimony
“In no case may we interpret an
action as the outcome of the
exercise of a higher psychical
faculty, if it can be interpreted as
the outcome of the exercise of
one which stands lower in the
psychological scale.”
In studying the digestive system, Pavlov came across an
important discovery about the nervous system--classical
conditioning.
Ivan Petrovich Pavlov
(1849 - 1936)
Pavlov’s Experimental Set-Up
Pavlov’s Dogs
Valiet
TungusBarbos
Edward Thorndike
Criticized Romanes’ views as
unscientific.
Problems with anecdotes:
1. Only a single case is studied. Does it
apply to whole species?
2. Observations are often not repeated or
repeatable
3. Conditions under which observations
are made are not well regulated
4. Do not know history of the animal
1874-1949
Thorndike (1874-1949)
The Puzzle Box
Law of Effect
• Some randomness to behavior (variability)
• Behaviors that lead to pleasurable
consequences are “stamped in”
• Those that have noxious consequences are
weakened.
John Watson (1878-1958)
Founder of behaviorism
• Published Psychology from the Standpoint
of a Behaviorist in 1919
• Pavlovian and instrumental conditioning
can explain much, if not all, behavior.
• Inferring internal states is redundant and
unecessary
• Cognitive explanations are not scientific
Watson’s famous quote:
Give me a dozen healthy infants, wellformed, and my own specified world to
bring them up in and I’ll guarantee to take
any one at random and train him to become
any type of specialist I might select -doctor, lawyer, artist, merchant-chief and,
yes, even beggarman and thief, regardless of
his talents, penchants, tendencies, abilities,
vocations, and race of his ancestors.
(Watson, 1930, p. 104)
B.F. Skinner: The rise of
behaviorism
•Feelings don’t cause behavior
•Often not aware of environmental causes
of our behavior
•Used behaviorist principles to explain
complex psychological phenomena
•E.g., language
•Advocated use of behavioral technology to
improve society.
Arguments against cognitive
approach
• Philosophical:
– Positing internal processes doesn’t add information
– Infinite # of cognitive models for any one phenomenon
– Purpose is to predict and control; what good do
cognitive models do?
• Empirical (testable):
– All behavior can be explained in terms of stimulusresponse learning
Why use animals?
• General process approach
• Control
• Continuity between species
• Today: Animal models of disease.
• Utility of studying many species