Behavioral and Evolutionary Perspectives
Behavioral
Perspective
Evolutionary Perspective
True or False?
T/F A single nauseating meal can give rise to a taste aversion that lasts for
years.
T/F During World War II, a psychologist created a missile that would use
pigeons to guide the missile to its target.
T/F Slot-machine players pop coins into the machines most rapidly when they
have no idea when they might win.
T/F You have to make mistakes to learn.
T/F Despite all the media hoopla, no scientific connection has been
established between violence in the media and real-life aggression.
Behavioral Perspective
Learning:
 A process through which experience produces lasting change in behavior
or mental processes.
Behavioral learning:
 Forms of learning that can be described in terms of stimuli and responses.
Neutral stimulus:
 Any stimulus that produces no conditioned response prior to learning.
Classical Conditioning
Creator: Ivan Pavlov



Pavlovian Conditioning
Respondent conditioning
S-R Psychology
"Essentially, only one thing in life is of real interest to us - our psychical experience. Its mechanism,
however, was and still is shrouded in profound obscurity.“
_______________________________________________________________
Basic Elements:
Unconditioned
stimulus (UCS)
Elicits a reflexive response in the absence of learning.
Unconditioned
response (UCR)
Reflexive response elicited by a stimulus in the absence of learning.
Conditioned
stimulus (CS)
Conditioned
response (CR)
Previously neutral stimulus that comes to illicit the CR.
Response elicited by a CS. Occurs after the CS is associated with a US.
Classical Conditioning
Principles of Classical Conditioning
• Learning that resulted
from pairing of a UCS
and a CS.
• Weakening and
eventual disappearance
of a learned response.
• Occurs when the CS is
no longer paired with
the UCS.
Acquisition:
Extinction:
• Reappearance of a
learned response after
its apparent extinction.
Spontaneous
recovery:
(1)
Acquisition
(CS + UCS)
(2)
Extinction
(CS alone)
(Time)
Trials
Rest period
Strength of the CR
(Weak)
(Strong)
Principles of Classical Conditioning
(3)
Spontaneous
Recovery
(CS alone)
Principles of Classical Conditioning
Higher-order conditioning:
 Procedure in which a neutral stimulus becomes a conditioned stimulus
through association with an already established CS.
Stimulus generalization:
 Similar CS elicits the CR.
Stimulus discrimination:
 Similar CS fails to elicit the CR.
Conditioned Fear
John B. Watson (1878-1958)
“Give me a dozen healthy infants, well-formed, 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
beggar-man and thief, regardless of his talents, penchants, tendencies, abilities,
vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so
have the advocates of the contrary and they have been doing it for many thousands
of years.”
Little Albert:
Fear as a learned response:

CS = Fluffy white rabbit/rat

UCS = Loud noise
Most effective when a US and CS are similar:

Nausea/Food vs. Shock/Food
Operant Conditioning
B. F. Skinner (1904-1990)

Radical Behaviorism
“To understand behavior we should focus on the external causes of
an action and the action’s consequences.”
Defined: Response becomes more or less likely to occur depending on its
consequences.
 Consequences are the most powerful influences on behavior.
Operant Conditioning
A response can lead to one of three types of consequences:
Neutral Consequence-Neither increases nor decreases the probability that the
response will recur.
Reinforcement-Consequence that causes a behavior to occur with greater
frequency.
Punishment-Consequence that causes a behavior to occur
with less frequency.
Reinforcement
Types of Reinforcers:
Primary Reinforcer: (food)

Stimulus that is inherently reinforcingTypically satisfying a physiological need.
Secondary Reinforcer: (money)

Acquired reinforcing properties through association with a primary reinforcer.
Types of Reinforcement:
Positive Reinforcement:

Response is followed by the presentation/increase in intensity of a reinforcing stimulus.

Response becomes stronger or more likely to occur.
Negative Reinforcement:

Response is followed by the removal, delay, or decrease in intensity of an unpleasant stimulus.

The response becomes stronger or more likely to occur.
Types of Punishers:
Primary Punisher: (shock)

Stimulus that is inherently punishing.
Secondary Punisher: (traffic ticket)

Acquired punishing properties through association
with other punishers.
SKINNER BOX


Developed to help test the principles developed in B. F.
Skinner’s theory.
Allows the experimenter to control
for all extenuating variables.
The difference between rats and people is that when a rat gets shocked at one end of a
maze, he never goes there again.
–B. F. Skinner, Harvard College Lecture, 1959
Principles of Operant Conditioning
Extinction:Weakening and eventual disappearance of a learned response.

Occurs when a response is no longer followed by a reinforcer.
Stimulus Generalization: Tendency for a response to occur in the presence of one stimulus but not
in the presence of other similar stimuli that differ from it on some dimension.
Discriminative stimulus: Signals when a particular response is likely to be followed by a certain type
of consequence.
Shaping: Successive approximations of a desired response are reinforced.

Successive approximations are behaviors that are ordered in terms of increasing similarity or
closeness to the desired response.
Instinctive drift: Tendency for an organism to revert to instinctive behavior.

Circus animals
Latent learning: Not immediately expressed in an overt response.

Occurs without obvious reinforcement.
Observational learning: Learns new responses by observing behavior of another rather than direct
experience.
Thorndike’s Law of Effect

Behavior consistently rewarded will become
learned behavior.
Learned Helplessness

Failure to take steps to avoid or escape from an unpleasant or
aversive stimulus that occurs as a result of previous exposure
to unavoidable painful stimuli.
Schedules of Reinforcement
Key Terms:

Continuous: FIXED
 A particular response is always reinforced.

Intermittent:VARIABLE
 A particular response is sometimes but not
always reinforced.

Interval: Amount of time.

Ratio: Number of responses.
Schedules of Reinforcement
Fixed Ratio (FR)
Rewards after a set amount of responses.
Variable Ratio (VR)
Rewards after a varied amount of responses.
Fixed Interval (FI)
Rewards after a fixed amount of time.
Variable Interval (VI)
Rewards after a varied amount of time.
Schedules of Reinforcement
Reciprocal Determinism
Creator: Albert Bandura
Observational Learning
Behavior Modification
Defined: Application of conditioning techniques to teach new responses or to reduce
or eliminate problematic behavior.
 Token society
Does Punishment Work?

When it does not work:
 Triggers aggression.
 Won’t produce the behavior only when the punisher is present.
 May inhibit learning new and better responses.
 Is often applied unequally.

When it works:
 Hot stove: Associate pain with it.
Rewards
Extrinsic Reinforcers:
•
Not inherently related to the activity being reinforced
•
Money, Prizes, and Praise
Intrinsic Reinforcers:
•
Inherently related to the activity being reinforced
•
Satisfaction of accomplishment
Don’t change a HOBBY into a JOB! (Bad idea)
Premack Principle:
 More probable behaviors will reinforce less probable behaviors.
Biological Components
Long-term potentiation:
 Biological process involving physical changes that strengthen the synapses
in groups of nerve cells.
 Neural basis of learning.
Ventral Tegmental Area:
 Dopamine
 Nucleus Accumbens
Hippocampus
Frontal Lobe
Violence and Media
Do violent movies change behavior?
Evolutionary
Perspective
Defined: Explains mental and psychological traits as adaptations and the functional
products of natural selection.
(John Locke, Charles Darwin)

Purpose: To bring the functional way of thinking about biological mechanisms into the
field of psychology.

Focus: How evolution has shaped the mind and behavior.

Application: Any organism with a nervous system.

Most research in evolutionary psychology focuses on humans.
Comparative Psychology: (Skinner, Albert Bandura)

Study of the behavior and mental life of animals other than human beings and
comparing their behavior to human life in order to better understand human behavior.
Ethology: (Konrad Lorenz, Niko Tinbergen, Karl von Frisch)

Study of animal behavior viewing humans as just another animal and attempting to
understand behavior in its natural environment.
Evolutionary
Perspective
Basic Definition:
 Any change in the combined genetic material in a population.



Evolution has occurred if there is any change in the population’s
gene pool.
Especially note that individuals do not evolve - populations evolve.
Evolution can easily be observed to occur within a species over
time.


Enough changes in the genetic material could occur in a population
over time that could result in the creation of a new species.
A species is defined as:



Group of similar organisms that share many characteristics.
Interbreed in nature.
Do not reproduce with organisms outside this classification.
Evolutionary
Perspective
Darwin’s Five Point Theory:

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A group of organisms tend to reproduce more offspring than the environment can support.
Most populations tend to remain fairly constant in size because of various population regulation
mechanisms at work. The population comes into an equilibrium with its present environment.
Competition takes place because so many individuals are introduced into an environment with
limited resources. There is a "struggle for existence." Such a competitive struggle for existence
usually includes being better adapted for obtaining the available resources in comparison to other
individuals. (Physical combat is not a very important part of this concept)
There exists variation among individuals within any species because genetic changes occasionally
occur that modify the DNA structure of chromosomes.
Variations caused by gene mutations are usually either harmful or useless. However, over the course
of time, beneficial mutations may occur. Individuals that inherit beneficial mutations or beneficial
gene recombinations are better adapted to survive. This is where the phrase "survival of the fittest"
comes in or the process of natural selection.
In a changing environment, those organisms with favorable genetic variations survive. The surviving
organisms then reproduce and transmit their DNA to their offspring. Over a long period of time
ENTIRELY
NEW SPECIES EVOLVE. Organisms that have successful genetic variations not only live longer but
produce
more offspring who also inherit the favorable adaptation.
Evolutionary
Perspective
Basic Point:
 Organisms that are better adapted (genetically) to their
environment will survive in greater numbers than those less well
adapted.
 The genetic material, therefore, that controls those adaptations
will become more numerous in the population in the next
generation.
 The ability of the entire group to survive in then increased.
 Natural selection is the preservation of favorable, beneficial
characteristics in the population and the elimination of the
unfavorable characteristics.