al nature".

C. B. Davenport, in his _Heredity and Eugenics_, presents evidence of
the importance of heredity in determining mental and moral traits.

Yerkes and Bloomfleld, in a short article in the _Psychological
Bulletin_ for 1910, Vol. 7, pp. 253-263, under the title, "_Do Kittens
Instinctively Kill Mice?_", furnish a good illustration of the method
employed in distinguishing native from acquired reactions.

{105}

CHAPTER VI

INSTINCT

CONDUCT AS DETERMINED BY NATIVE REACTION-TENDENCIES

Instinct is native behavior. It is contrasted with habit, knowledge,
or anything in the way of learned reactions. When the mother wasp
gathers a store of food suitable for young wasps, lays eggs beside the
food and covers the whole with a wall of mud, we know that her
behavior is instinctive because she has had no possible chance to
learn from older wasps. She has never seen a wasp's nest made, for
when the last preceding crop of nests was being made she was herself
an unhatched egg. Therefore, she cannot possibly know the use of the
nest with its eggs and store of food. She has no "reason" for building
the nest, no ulterior purpose, but is impelled to build the nest,
simply and solely for the sake of doing just that thing. Thus instinct
is contrasted with calculated or reasoned action as well as with
learned action. Calculated action is based on knowledge of cause and
effect, and this knowledge is acquired by the individual in the course
of his experience; but instinct is not based on the individual's
experience, but only on his native constitution.

The case of the baby eating is exactly the same as that of the wasp.
The baby has not learned to eat, he knows nothing of the use of food
and therefore has no ulterior purpose in eating, he does not reason
about the matter, but eats simply because hunger is a native impulse
to eat. {106} Eating is an end in itself to a hungry baby, and not a
means to some further end; and that is what eating continues to be
even to the hungry adult, however much he may learn about the use of
food in maintaining life. From a broad philosophical point of view,
instinct may be seen to work towards some great end, such as the
preservation of the individual or the propagation of the race, but
from the individual's own point of view, it is directed simply towards
the performance of some particular act, or the accomplishment of some
particular result.

If instinct, as a collective term, means