The aim of the paper is to show that research on temperament is inescapably
bound with the concept of trait as applied in personality research. It is
the individual differences approach on which temperament studies are based,
and traits are the basic units by means of which these differences are des
cribed. Taking as a point of departure the definition of trait understood a
s a relatively stable and individual-specific generalized tendency to behav
e or react in a certain way expressed in a variety of situations, the hypot
hetical status of temperament traits is discussed. Special attention is pai
d to states and behaviour by means of which temperament traits are inferred
as well as to the biological and environmental determinants of these trait
s. Temperamental traits constitute only a part Of the personality structure
viewed from the perspective of individual differences and this perspective
is only one of the many from which the complex nature of personality shoul
d be viewed. Copyright (C) 2001 John Wiley & Sons, Ltd.