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528 Jean Piaget
KLUCKHOHN and F. F. STRODTBECK; their significance may be ascertained by
reference to the well-known works of Stevens who, in psychology, has endeavoured
to construct a kind of subjective psycho-physics.
31. Avant-garde schools, such as the Polish school, being of course duly excepted.
32. Without wishing to refer here to the mathematical aspects of feedbacks, we may
recall that in the case of this simple model the transfer function is in the form
F(p) = where p = a+iW and for the ‘free variations’ of the system F(p) = I,
S
hence W = o and a = - in the absence of sinusoidal fluctuations. The latter
would appear if delayed reactions between variables were introduced.
33. Supposing that G(t) represents State demand (negative in the case of subsidy), one
dY(t)
would obtain, for example, C(t) = -g. -or g > 0, which would constitute a new
dt
feedback allowing the rate of growthfto be increased in the form p‘ =
34. Let us note further that H. A. Simon (‘On the Application of Servomechanism in the
Study of Production Control’, Econometrica 20, 2, 1952, pp. 247-268) has tried to
formulate, in situations of a dynamic kind, decision criteria enjoying certain properties
of stability. He thus arrived at a loop system making it possible to determine
qualitatively a criterion whose intuitive meaning is immediate: the rate of production
must be increased or diminished proportionally to the deficit or surplus of
effective stocks as compared with optimum stocks and proportionally to the variations
of that deficit or surplus.
35. Cf.,inter alia H. A. Simon’s well-known formalization of Festinger’s experiments on
communication in small social groups.
36. Logique et connaissance scienti’que (EncyclopBdie de la Plkiade), pp. 879-880.
37. It should even be remembered that biologists speak of the transmission of information
as early as the genome level, the signifiant then depending on the order of
the sequences in the DNA code (Watson and Crick).
38. And collectively as well as individually pre-speech, for among themselves the
young deaf-mutes build up a language of gestures.
39. See H. SINCLAIR, Acquisition du language et ddveloppement de la pensde, Dunod,
1967.
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