Transcript Behaviorism - Michael Johnson's Homepage

Behaviorism
METHODOLOGICAL BEHAVIORISM
Classical Conditioning
While investigating the
digestion of dogs, Ivan
Pavlov (1849-1936)
observed that the dogs in
his laboratory would
salivate when they saw
the people who brought
their food.
Classical Conditioning
Pavlov theorized that he
could make the dogs
salivate to any thing or
event, if he had first
presented it with food.
Animal Behavior vs. Psychology
Pavlov won a Nobel prize in physiology and
medicine for this work.
He was a physiologist, not a psychologist.
At the time, psychology was mostly the study of
conscious experience (e.g. William James).
Associationism
Pavlov’s research suggested something like this:
Animal behavior is controlled by the
environment. Animals are born behaving in
certain natural way, and learned behavior is
through a process of association.
Introspectionism
At the time, psychology was focused on individuals
reporting details of their conscious experience. To
make this rigorous, there was a heavy focus on
expertise:
• Wundt required his subjects to perform 10,000
introspective observations before they were
considered sufficiently trained.
• Titchener wrote 1000 page training manual for
experimental introspection.
Training was supposed to provide subjects with:
• An increased capacity for attention
• An ability to properly distinguish such facets of
experience as ‘tonal intensity’ and ‘tonal
clearness’
• An ability to avoid confusions such as ‘stimulus
error’ – the description of the object
experienced as opposed to the experience
itself.
Famously, however, none of the psychological
labs got the same results! For example, they
couldn’t agree whether one could introspect
imageless thoughts.
John B. Watson
The American psychologist
John B. Watson was the
progenitor of
methodological
behaviorism.
Psychology as the Behaviorist Views It
In “Psychology as the Behaviorist Views It,” Watson recharacterizes psychology as:
• ‘purely objective’
• ‘a branch of natural science’
• Concerned with ‘prediction and control of behavior’
• NOT concerned with conscious states
• Opposed to introspection
• Recognizing no difference between human and
animal
Watson’s Critique of Introspectionism
“If you fail to reproduce my findings, it is not due to
some fault in your apparatus or in the control of your
stimulus, but it is due to the fact that your
introspection is untrained… If you can't observe 3-9
states of clearness in attention, your introspection is
poor.” (pg. 6).
Behaviorism
The conclusion Watson draws is very extreme:
we must get rid of all references to
consciousness. We shouldn’t even use terms like
‘mental state’, ‘consciousness’, ‘mental image’,
or even ‘mind’. These aren’t scientific terms.
The vocabulary of psychology should only
involve terms for behavior, stimulus, and so on.
Psychology, according to the behaviorist, is
about the control and prediction of behavior.
B. F. Skinner
B.F. Skinner was an
influential behaviorist
after Watson. He believed
that mental states were
explanatorily inert and
that society could and
should be structured in a
way to control people’s
behavior.
Operant Conditioning
Classical conditioning sets up an association
between two external stimuli.
Operant conditioning sets up an association
between a behavior and a subsequent
reward/punishment.
Skinner Box
The Law of Effect
Rewarded behaviors increase in frequency,
punished ones decrease.
Cf. Darwin & the prevalence of traits.
Skinner’s Radicalism
Watson was primarily concerned with
methodology – we shouldn’t talk about internal
mental states because they cannot be
objectively studied.
Skinner believed that we shouldn’t talk about
internal mental states because the entirety of a
person’s behavior can be explained in terms of
the stimuli in their environment – internal
mental states don’t have an explanatory role.
Are Mental States Suspect?
We can’t see or hear or feel or taste mental
states. The methodological behaviorists
assumed they were therefore not objective or
scientific.
BUT, lots of unobservable things are completely
objective and scientific: electrons, dinosaurs, the
earth’s core.
AGAINST METHODOLOGICAL
BEHAVIORISM
Chomsky vs. Skinner Part 1
Noam Chomsky wrote an
influential critique of
Skinner’s views.
In particular, he argued
that stimuli didn’t control
our behavior. From one
stimulus, lots of behaviors
were possible.
The Rembrandt
•
•
•
•
“Dutch.”
“Wow!”
“It’s a Rembrandt.”
“This old stuff really
bores me.”
• “Let’s steal it!”
• “Can you believe the
city paid $32 million
USD for that?”
Chomsky vs. Skinner Part 2
Chomsky thought the environment didn’t
directly control your behavior– your mental
states mattered too.
In particular, he thought that we had innate (inborn) knowledge that determined our behavior.
Universal Grammar
Chomsky thought that in
order to learn a language,
you had to know in
advance that certain thing
were impossible, because
you were very unlikely to
get evidence that agreed
or disagreed with them.
PHILOSOPHICAL BEHAVIORISM
Philosophical Behaviorism
According to the philosophical behaviorists,
mental states do exist.
But mental states aren’t private things: they are
dispositions to behave in certain ways.
Dispositions
Philosophical Behaviorism
You believe that a lion is near = you run away OR
you pull out your gun OR you climb a tree OR
you say “there’s a lion” OR… when you see/
hear/ touch/ taste/ smell a lion.
You are afraid of the dark = you scream OR you
tremble OR you cry OR you turn on the lights
OR… when you are in the dark.
MSs Don’t Cause Dispositions
Ravenscroft makes clear that according to
behaviorism, pain doesn’t cause me to say
“ouch” when I’m hit.
Pain = me saying “ouch” when I’m hit.
Not about Finding Out
It’s normally true that I find out about other
people’s mental states by observing their
behavior.
But normally we think we observe their
behavior.
The philosophical behaviorist thinks we observe
their mental states!
1. Physical Events Cause MSs
Ravenscroft says this is a plus for behaviorism:
supposedly states of the world cause MSs. E.g.
standing on a tack causes pain.
But is this true? Does standing on a tack cause
me to have the disposition that when I stand on
a tack, I say “ouch”? Usually I have that
disposition prior to standing on tacks.
2. Some MSs Cause Actions
The glass broke when I dropped it because it
was fragile. (Is this just Moliere again?)
5. MSs Represent Things
“The English word ‘dog’ expresses the property
of being a dog… This semantical fact about
English reduces to a certain fact about the
behavioral dispositions of English speakers; viz,
that their verbal response ‘dog’ is… under the
control of dogs.” – Fodor, “A Theory of Content
I,” describing Skinner’s view.
MSs Correlated with Brain States
Analogy: fragility correlated with molecular
structure. (Dispositional and categorical
properties.)
1st Argument for Phil. Behaviorism
People’s behavior in certain circumstances is
evidence for what mental states they have or
lack. (E.g. wanting or not wanting something.)
If their mental states = behavior in certain
circumstances, then it’s obvious why that is.
1st Argument for Phil. Behaviorism
(Obviously this argument isn’t conclusive. No
one thinks electrons are dispositions to bond in
certain circumstances.)
Empiricist Criterion of Cognitive
Significance
According to the logical positivists, in order for a
sentence to have cognitive significance (to be
meaningful), it had to have verification
conditions.
(‘Verification’ is a Latinate English word < ‘veri-’
true + ‘facere’ to make. Verification conditions
are conditions under which the truth of a
statement can be conclusively established.)
Empiricist Criterion of Cognitive
Significance
In fact, the positivists maintained that the
meaning of a sentence was its verification
conditions. So a sentence with no verification
conditions– where no experience can establish
its truth– is meaningless.
Truth vs. Verification
Many philosophers (even today) have identified
the meaning of a sentence with its truth
conditions. These are the circumstances in
which the sentence would be true. But the
positivists went farther– they held that the
meaning of a sentence was its verification
conditions– the circumstances in which we
would know the sentence was true.
The Elimination of Metaphysics
This was part of a radical philosophical agenda,
which included “the elimination of
metaphysics.” The idea was to view many
philosophical problems of the past (and also
many religious claims) as meaningless disputes
that could simply be ignored.
The Elimination of Metaphysics
Example: In a religion where God is beyond
human experience, the positivists would say
that “God exists” is neither true nor false but
meaningless, since no experience could verify it.
Kant, Hegel, and Heidegger were also big targets
for the positivists. Example Hegel quote: “But
the other side of its Becoming, History, is a
conscious, self-meditating process — Spirit
emptied out into Time.”
Positivism for Behaviorism
Since the way we discover whether people are
in pain, believe that it’s raining, want coffee, etc.
is by observing their behavior in certain
circumstances, “X wants coffee” means “X drinks
coffee when…”
AGAINST PHILOSOPHICAL
BEHAVIORISM
Logical Relations
From:
1. If Joe fails the final exam, he will fail the course.
2. If Joe fails the course, he will not graduate.
It follows logically that:
3. If Joe fails the final exam, he will not graduate.
Logical Relations
If you believe:
1. If Joe fails the final exam, he will fail the course.
2. If Joe fails the course, he will not graduate.
These beliefs can cause you to also believe:
3. If Joe fails the final exam, he will not graduate.
Rationality
It’s not clear how behaviorism can explain the
rationality of mental processes.
We can have dispositions to behave in all sorts
of ways that aren’t rational. (Outside control
doesn’t respect rationality.)
Consciousness
Paralyzation and surgery. (Cf. Super-stoics.)
Consciousness
Pretending to feel pain.
Behavior Depends on LOTS of MSs