Main trends of research in the social and human ... - unesdoc - Unesco

28 Jean Piaget
A. Of all the sciences of man, the only one which is not affected by this fundamental
difficulty is demography, in which the yardstick is the number of
individuals possessing a given characteristic. But it is precisely because, in such
cases, the statistical methods utilized may be kept relatively simple (despite the
complexity of certain problems of growth), that such methods cannot be applied
without further ado to other sectors of the human sciences. Consequently demographic
studies, although of basic importance to economic and sociological
research, remain relatively hermetic,Io although fruitful, the impossibility of
experimentation (in the strict sense of a dissociation of factors) being compensated
for by the relative precision of measurements and the success of the different
statistical methods applied to variations and to the different functional
relationships open to calculation.
B. Scientific psychology is, in some respects, diametrically opposed to
demography, in the double sense that whilst experimentation is relatively
simple, there is an almost total lack of unities in which formative or functional
processes themselves may be measured. Experimentation is, as we have stated,
of the same type in biology as in psychology, since it concerns behaviour, which
is one aspect of life in general. It is relatively feasible in certain cases to bring
about variation in a single factor or a single group of factors, the others being
more or less neutralized; the difficulty here is to maintain a situation of ‘all
other things being equal‘, since organisms, like behaviour, are functional entities
whose elements are more or less interdependent. In the case of human behaviour,
the impossibility, on occasion, of dissociating factors is due as much
to moral as to technical considerations; but pathological states frequently
provide the experimenter with what he cannot obtain through actual experimentation:
aphasia, for example, or deaf-mutism are, in fact, the expression of a
dissociation between language and thought. Moreover, if the human subject is
less amenable to manipulation than the animal, he does have the great advantage
of being able, as a general rule, to describe verbally a part of his own
reactions. As far as the historical or diachronic dimensions of psychology are
concerned, if the paleontology and prehistory of man provide virtually no information
with regard to mentality (unless we follow Leroi-Gourhan’s example
in seeking to reconstitute intelligence through the study of techniques), the
psychology of individual development can make use of experimentation at all
age-levels, and is thus an inexhaustible mine of knowledge concerning formative
mechanisms.
On the other hand the main difficulty in psychology lies in the lack of unities
of measurement. It is true that the ‘test’ method, together with countless ‘psycho-physical’
procedures, provide a wealth of data which are termed metric
because they are solely concerned with aspects of behaviour which can be
measured, i.e. with the resultants of reactions or, as some would say, with ‘performance’.
But, even if we confine ourselves to such resultants, we are still
unable to talk of unities of measurement: if, for example, a subject retains 8
words out of 15 in a memory test, or 4 out of 6 sectors of a spatial journey, we
have no means of knowing whether these words or sectors are equivalent as between
each other, nor do we know how to compare the memory of words with