The schedule of reinforcement also plays a criti-
cal role in affecting response rates. There are two
types of reinforcement schedules: interval schedules
and ratio schedules. Interval schedules are reinforce-
ment schedules in which rewards are given after a cer-
tain period of time. Ratio schedules are schedules in
which rewards are given after a specific number of
correct responses. As seen below, the time interval or
response ratio can either be fixed or variable.
The schedule that elicits the most rapid frequen-
cy of responses is the fixed ratio schedule. In this case,
the animal knows it will receive a reward after a fixed
number of responses so it produces that number as
quickly and frequently as possible. This phenomenon
also occurs with people; if craftspeople are paid for
each object they make, they will try to produce as
many objects as possible in order to maximize their
rewards.
Generating nearly as rapid a frequency of re-
sponses as the fixed ratio schedule is the variable ratio
schedule. In this case, the number of responses need-
ed to produce a reward varies so the animal or person
will emit the desired behavior frequently on the
chance that the next time might bring the reward.
Lotteries and slot machines function on a variable
ratio schedule, thus inducing people to want to play
again.
Interval schedules tend to produce slower fre-
quencies of response. A fixed interval schedule will
produce fewer responses early in the interval with an
increase as the time for the reward approaches. One
example in human behavior is the passing of bills in
Congress. As elections approach, the number of bills
passed increases dramatically, with a swift decline
after the election. A variable interval schedule, on the
other hand, produces a slow but steady frequency of
response; for instance, a teacher giving ‘‘pop’’ quizzes
at irregular intervals encourages her students to
maintain a consistent level of studying throughout the
semester.
Although classical or respondent conditioning in-
volves automatic responses to behavior, operant or in-
strumental conditioning is a result of the decision to
produce a certain behavior in order to receive a re-
ward or avoid a punishment.
Observational Learning
Learning does not always occur directly as a result
of punishment or reinforcement, but can occur
through the process of watching others. Children can
learn from observing rewards or punishments given
to someone else, and do not need to be the recipients
themselves. This form of social learning is called ob-
servational learning. The terms ‘‘imitation’’ and
‘‘modeling’’ are often used interchangeably and are
types of observational learning.Imitation and Modeling
Imitation may be a powerful means through
which infants can learn from those around them. An-
drew Meltzoff and M. Keith Moore’s classic 1977
study illustrated imitation of tongue protrusion, lip
protrusion, and mouth opening by two- to three-
week-old infants. For this behavior to occur, infants
must match what they see the model doing with what
they feel themselves doing, and it has been demon-
strated in infants three days old. Thus, it seems that
imitation occurs from birth onward and that infants
may learn many new behaviors in this way.
As children grow, they imitate more complex be-
haviors than simple mouth movements. A researcher
who has performed much research in the area of ob-
servational learning in children is Albert Bandura.
His best-known study of modeling in children in-
volved aggressive behavior. While children observed,
models either physically attacked or nonaggressively
interacted with a large inflatable doll called Bobo.
The children were then given the opportunity to play
with Bobo. Those who had observed the aggressive
model displayed twice as much aggressive behavior as
those who had observed the nonaggressive model. In
addition, the children who had observed the aggres-
sive model performed aggressive acts that had not
been modeled, illustrating that generalization had oc-
curred. These findings indicate that children can in-
deed learn what behavior is appropriate in a given
situation through observation alone.
Observational learning can have other effects as
well. The opposite of the Bobo findings can occur in
which inhibition of a class of behaviors becomes less
likely after observation. Often inhibition occurs after
observing another person being punished for per-
forming a certain type of behavior, such as aggressive
behavior in general.
Through his studies on observational learning,
Bandura developed his cognitive theory of observa-
tional learning. He posited that four mental processes
need to be present in order for observational learning
to occur. One mental process is that of attention; that
is, a child must find the model interesting enough to
hold the child’s attention. The child must also be able
to hold the model’s behavior in memory in order to
imitate the behavior later. In addition, without suffi-
cient motor control, the child would be unable to
mimic the model’s behaviors. Finally, motivation is
integral in that the child must have a reason to per-
form the behavior that was modeled.
Bandura’s cognitive theory of observational
learning is helpful for understanding why children238 LEARNING