or. The cat, in learning the trick of escaping from a cage by
turning the door-button, makes and therefore exercises a variety of
reactions; and you might expect, then, in accordance with the law of
exercise, that all of these reactions would be more and more firmly
linked to the cage-situation, instead of the successful reaction
gradually getting the advantage and the unsuccessful being eliminated.
The law of effect, stated as objectively as possible, is simply that
the successful or unsuccessful outcome or _effect_ of a reaction
determines whether it shall become firmly linked with the stimulus, or
detached from the stimulus and thus eliminated. _The linkage of a
response to a stimulus is strengthened when the response is a success,
and weakened when the response is a failure_.

Success here means reaching the goal of an awakened desire or
_reaction-tendency_, and failure means being stopped or hindered from
reaching the goal. Since success is satisfying and failure unpleasant,
the law of effect is often stated in another form: a response that
brings satisfaction is more and more firmly attached to the situation
and reaction-tendency, while a response that brings pain or
dissatisfaction is detached.

The law of effect is a statement of fact, but the question is whether
it is an ultimate fact, or whether it can be explained as a special
case of the law of exercise. Some have suggested that it is but a
special case of the sub-law of frequency; they call attention to the
fact that the successful response must be made at every trial, since
the trial continues till success is attained, whereas no one
unsuccessful response need be made at every trial; therefore in the
long run the successful response must gain the frequency advantage.
But there is a very ready and serious objection to this argument; for
it may and does happen that an unsuccessful response is repeated
several times during a single {393} trial, while the successful
response is never made more than once in a single trial, since success
brings the trial to a close; and thus, as a matter of fact, frequency
often favors the unsuccessful response--which, nevertheless, loses out
in competition with the successful response.

Can the law of effect be interpreted as an instance of the sub-law of
recency? The successful reaction always occurs at the end of a trial,
and is the most recent reaction at the beginning of the next trial.
This recency might have considerab