This report describes an evolution of research methodology for adducing evi
dence regarding whether the self functions as a control system. While there
has been a great number of studies in the literature on personality and so
cial psychology aimed at demonstrating that behavior of many kinds can be a
ffected by focusing attention upon the subject's self-concept, or by challe
nging or threatening it, little attention has been given to the question of
why this would be so. A proposed explanation would be that the self functi
ons as a control system. Testing this hypothesis has entailed development o
f a methodological approach in which control action occurs predictably rath
er than having a statistical probability. This has required defining a mode
l and testing it by predictions rather than attempting to isolate underlyin
g variables with multivariate techniques. (C) 1999 Academic Press.