Download LCS 11: Introduction to Cognitive Science. Behaviorism

LCS 11: Introduction to Cognitive Science.
Behaviorism
Jesse Harris
February 11, 2013
Background to behaviorism
Much of philosophy has addressed what is sometimes known as
‘Plato’s problem’ – how do we come to know so much about the
world, given our limited experience? Two important, though not
necessarily mutually exclusive, strands of response are rationalism,
with privileges reason over experience, and empiricism, which favors
experience over reason.1
Rationalism
How do we know so much about the world given our limited experience? The rationalists propose that knowledge is deductive, in that we
may glean knowledge from principles independent of experience.
Rationalism
Knowledge is to be gained primarily through reason alone.
With respect to questions of mind, rationalism is often associated
with René Descartes, who modeled his method on geometric proofs
from Euclid.2 Descartes wished to determine an incontrovertible
foundation of knowledge which was free of the possibility of illusion
from the senses and which supported the immortality of the soul.
Descartes famously settled on a foundation of knowledge through
the idea that, even if illusory, a thought must have a thinker: the very
act of doubt verified some aspect of his existence! In other words,
cognito ergo sum. There are three important methodological assumptions that Descartes made:
1. Knowledge can be determined independently of the senses;
2. Ideas are transparent to conscious introspection;
3. We should privilege that which could be established by pure
thought, e.g., mathematical truths, over the sense data of experience
Substance dualism
The mind (soul) is a immaterial, immortal substance which exists
independently of the body.
1
In the Meno,
Plato adopts a rationalist approach, arguing that knowledge is innately given
and that the soul relies on experience
and reason to recollect that knowledge.
His argument is illustrated by getting
a slave to “recollect” how to determine
the areas of embedded squares like
those above.
Euclid’s highly influential The Elements
deduces Euclidean geometry from a
limited set of axioms. Descartes and
others seemed to consider the axiomatic
method developed by Euclid to be the
ideal form of scientific inquiry.
2
lcs 11: introduction to cognitive science. behaviorism
Despite deeply ingrained problems with this view, substance dualism
remains a popular view.3 An alternate, and just as venerable, view
is known as empiricism, which treats the acquisition of knowledge as
inductive.
2
Three prevalent considerations are as
follows (see Cunningham, 2000, ch. 1)
3
1. Reliance on introspection
2. Causal separation
Empiricism
3. Development of mind
In contrast to rationalists, empiricists largely reject the assumption
that ideas are innate. Instead, mental contents are derived from two
factors.
1. Sensations – events with external causes.
2. Reflection – mental operations that associate external or internal
states with other internal states.
Together, these factors yield Ideas, mental contents likened to pictures
or images, linked to what they are about.
Empiricism
Knowledge is to be gained primarily through sense experience.
A prominent proponent of empiricism was John Locke, who devised
a scheme for mental mechanics in which ideas come to be associated
with one another. Through this kind of associationism, as it was called,
simple ideas compose to form more complex ones.
“Let us then suppose the mind to be,
as we say, white paper, void of all
character, without any ideas. How
comes it to be furnished? . . . I answer,
in one word, experience. In that, all our
knowledge is founded, and from that it
ultimately derives itself.”
Essay Concerning Human Understanding
John Locke (1689)
Introspectionism
Interestingly enough, the earliest experimental psychologists adopted
elements, from both traditions. For example, Wilhelm Wundt and
his student E. B. Titchener4 developed a method known as introspection, in which the contents of experience were reflected on during
conscious investigation and reported back. In an attempt to make
this process more scientific, participants were trained in introspection through many trials, reporting their subjective experience.5 In
particular, participants were instructed to decompose the process
into discrete stages: perception of stimulus, a search for a response,
identification of response, production of response, and so on.
Exercise: Try this for yourself. View this
swatch of red and reflect on the experience,
attempting to break down the experience into
as many components as you can.
4
Wilhelm Wundt
(1832–1920)
E. B. Titchener
(1867–1927)
“The first order of the psychologist
. . . is to ascertain the nature and number of mental elements. He takes up
mental experience, bit by bit, dividing
and subdividing, until the division
can go no further. When that point
is reached, he has found a conscious
element.”
5
An Outline of Psychology
(Titchener, 1896)
lcs 11: introduction to cognitive science. behaviorism
3
Behaviorism
Frustration and disillusionment with introspection as a method of
gaining entry into mental processes quickly mounted.6 John Watson and, later, B. F. Skinner,7 led the charge against the subjectivity
seemingly inherent to the introspective method.8 They proposed a
purely behavioristic approach to studying the cognition, concerned
in no small measure with the prediction and control of behavior.
As discussed in Cunningham (2000), multiple kinds of behaviorism
resulted, notably, Methodological and Metaphysical Behaviorism.
Methodological behaviorism
A scientific study of mind should eschew talk of the mind in favor
of a description of behavior, since only behavior provides publicly
observable, hence potentially verifiable, data.
“Take the case of sensation. A sensation is defined in terms of its attributes.
One psychologist will state with readiness that the attributes of a visual
sensation are quality, extension, duration and intensity. Another will add
clearness. Still another that of order. I
doubt if any one psychologist can draw
up a set of statements describing what
he means by sensation which will be
agreed to by three other psychologists
of different training.“
6
Psychology as the Behaviorist Views It
(Watson, 1913)
7
Metaphysical behaviorism
Mental events are reducible in kind to behavior: there is no substance
or thing corresponding to what we call ‘mind.’
Influenced by the Vienna Circle’s circumscribed view of science,9
behaviorism seeks to align, to various extents, the study of mind with
the study of behavior. That is, instead of worrying about the connection between mind and body, we focus on what we can observe:
responses to external stimuli. Among the vocabulary central to Skinner’s behaviorism was operant conditioning, in which modification of
behavior is voluntary. Skinner developed the so-called “Skinner box”
to control an animal’s environment, typically a pigeon or white rat,
starve them to create a “drive,” and then wait for animal to discover
a relation between the environment, e.g., a lever, and a reward, e.g., a
food pellet. Soon enough, the behavior is associated with the reward.
John B. Watson
(1878–1958)
B.F. Skinner
(1904–1990)
“Psychology as the behaviorist views
it is a purely objective experimental
branch of natural science. Its theoretical
goal is the prediction and control
of behavior. Introspection forms no
essential part of its methods, nor is the
scientific value of its data dependent
upon the readiness of with which they
lend themselves to interpretation in
terms of consciousness. The behaviorist
. . . recognizes no dividing line between
man and brute.” Ibid.
8
The Vienna Circle refers to a group
of philosophers and scientists in Vienna in the early 1920s who sought to
eliminate what they deemed logical
mistakes from philosophical questions.
They thought that ambiguous language
had radically misled scientific and
philosophical inquiry, and proposed
a unified science built on the foundation of symbolic logic and publicly
observable sense experience.
9
In addition, Skinner placed animals on a schedule of reinforcement.10
If a pigeon is fed at regular intervals regardless of its behavior, it will
adopt essentially arbitrary patterns of behavior which it has associated with the reward, such as spinning, pecking, etc. The efficacy of
the association could be manipulated by varying the rate of reward:
10
Skinner, B. F. (1948). ‘Superstition’
in the pigeon. Journal of Experimental
Psychology 38, 168–272
lcs 11: introduction to cognitive science. behaviorism
fixed and random reinforcement. The strongest type was random reinforcement, in which the animal is rewarded at random intervals.
Indeed, it sometimes happened that although feeding device was dismantled, the pigeon indefinitely continued to perform the behavior
that was associated with the reward.
Thus, the behaviorist was able to account for admitedly simple
behavior without recourse to unsightly mentalistic terms like desire,
belief, and so forth. That is, the psychologist needn’t speculate about
what the bird was feeling; she only needed to report its behavior.
Encouraged by the success with pigeons and rats, Skinner and colleagues proposed that the basic mechanism of association between a
stimulus and response was the central, or even sole, mechanism driving all behavior, even in human beings. Skinner even claimed that
language learning was simply an instance of operant reinforcement,
albeit complex in nature. For example, a child might be rewarded
by her parents to cry out Papa in the presence of her father, thereby
associating the word with the figure. In a devasting review by Noam
Chomsky,11 it soon became apparent that Skinner’s science of behavior was simply not rich enough to account for more complex forms of
speech or human behavior.
Indeed, even once committed behaviorists like Keller and Marian Breland12 observed that instinctive behaviors not driven by the
external environment were a powerful determinant of an animal’s
action. It is important to note that the success of behaviorism owes to
a specific historical and cultural context, in that it opposed the deterministic, predjudice-driven psychological theories sweeping Europe
at the time, most notably those associated with Nazism. At its core,
behaviorism was an optimisitic approach to science, offering a vision
of re-engineering society through simple mechanisms entirely under
the individual’s control. May it rest in peace.
References
Breland, K. and M. Breland (1961). The misbehavior of organisms.
American Psychologist 16, 681–684.
Chomsky, N. (1959). Verbal Behavior. By B. F. Skinner. Language 35,
26–58.
Cunningham, S. (2000). What is a Mind? An Integrative Introduction to
the Philosophy of Mind. Indianapolis: Hackett Publishing.
Skinner, B. F. (1948). ‘Superstition’ in the pigeon. Journal of Experimental Psychology 38, 168–272.
Titchener, E. B. (1896). An Outline of Psychology. Macmillian.
Watson, J. B. (1913). Psychology as the behaviorist views it. Psychological Review 20, 158–177.
4
Chomsky, N. (1959). Verbal Behavior.
By B. F. Skinner. Language 35, 26–58
11
Noam Chomsky
(b. 1928)
Chomsky’s review is
widely regarded as
the death knoll for
behaviorism, making commonsense,
mentalistic talk once
again respectable in
American psychology.
Breland, K. and M. Breland (1961).
The misbehavior of organisms. American Psychologist 16, 681–684
12