behavior, or of such adaptive behavior in monkeys and apes as
corresponds to the ideational behavior of man. It was my plan to
determine, so far as possible in the time at my disposal, the existence
or absence of ideas and the rôle which they play in the solution of
problems by monkeys and apes. I had in mind the behavioristic form of
the perennial questions: Do these animals think, do they reason, and if
so, what is the nature of these processes as indicated by the
characteristics of their adaptive behavior?

My work, although obviously preliminary and incomplete, differs from
most of the previous studies of the complex behavior of the infrahuman
primates in that I relied chiefly upon a specially devised method and
applied it systematically over a period of several months. The work was
intensive and quantitative instead of more or less incidental, casual,
and qualitative as has usually been the case. Naturally, during the
course of my special study of ideational behavior observations were made
relative to various other aspects of the life of my subjects. Such, for
example, are my notes on the use of the hands, the instincts, the
emotions, and the natural aptitudes of individuals. It is, indeed,
impossible to observe any of the primates without noting most
interesting and illuminating activities. And although the major portion
of my time was spent in hard and monotonous work with my experimental
apparatus, I found time each day to get into intimate touch with the
free activities of my subjects and to observe their social relations and
varied expressions of individuality. As a result of my close
acquaintance with this band of primates, I feel more keenly than ever
before the necessity of taking into account, in connection with all
experimental analyses of behavior, the temperamental characteristics,
experience, and affective peculiarities of individuals.