The Study of Instinct: By N. Tinbergen. London and New York: Oxford University Press, 1951. 228 pp.

This is a very meritorious book. It does not, however, deal with the psychoanalytic concept of instinct (i.e. 'drive') but with the original meaning of 'unlearned behavior' (i.e. inherited neural mechanisms, similar to Pavlov's 'unconditioned reflexes'). This is a field analysts have side-stepped consistently because they have investigated the causes of acquired behavior based on the history of the individual. As motives of behavior psychoanalysis used the concept of Trieb which was sometimes translated into English as 'instinct', sometimes as 'drive'. Only the latter comes near to Freud's use of Trieb which means a hypothetical energy of biological nature with specific aims. Those aims were grouped in two classes, destructive and libidinal (sexual) ones, and accordingly sexual drive (libido) and destructive drive were the hypothetical pillars on which psychoanalytic theory of drives, i.e. energies with a purpose, was erected.

Pavlov on the other hand treated all acquired behavior as modifications of inherited mechanisms which he called unconditioned reflexes. The personal experience of the individual which modified this unlearned behavior he understood as a 'conditioning' process which he viewed as being entirely mechanistic because he eliminated subjective motivations (pleasure and pain, desire and rejection, hope and fear) as objectively not observable and, accordingly, 'unscientific'.

Pavlov thus eliminated an important part of psychology, namely subjective motivation, whereas Freud, as the reviewer has frequently pointed out,1 used an untenable hypothetical figment, Trieb, on which to build his psychology. Freud felt that he had his hands so full with finding out how experience modifies the individual that he purposely left out inherited mechanisms, and consequently failed to respond to early overtures from Pavlov who had great admiration for Freud's first publications. He thus missed developing acquired behavior from hereditary behavior and had to resort