1) Do healthy individuals scoring relatively high on TA
and healthy individuals scoring relatively low on PA
report more fear of the safe CS movement at the
beginning of extinction as compared with the end of
acquisition, but not to the painful CS1 movement? 2)
Do the slopes of the fear ratings for the CS movement
during the course of extinction differ for people with
relatively high versus low TA and relatively high versus
low PA, with steeper slopes for high TA and low PA?
3) Does relatively high PA buffer the negative impact
on safety learning in healthy individuals scoring relatively
high on TA? A few remarks are needed to clarify
these hypotheses. First, with respect to the traits examined,
we do not believe in the rigid expression of traits,
that is, the same expression in any kind of situation, but
rather in a flexible expression that depends on the trait–
environment interaction (‘‘strong vs weak situation’’)31—an
idea that has received plenty of empirical
support. We assume that the emergence of individual
differences would be facilitated in weak or ambiguous
situations; in this case, the uncertainty is greatest at
the beginning of the extinction phase, as the contingencies
change. Second, the questionnaire scores are
not truly ‘‘high’’ from a clinical point of view, but instead
concern ‘‘relatively’’ high and low scores, with this
healthy study sample as a reference. Furthermore, the
current analyses involve continuous measures of the
trait variables, and thus the conclusions should be