J. Romanus et T. Garling, Do changes in decision weights account for effects of prior outcomes on risky decisions?, ACT PSYCHOL, 101(1), 1999, pp. 69-78
When a prior outcome in a sequence of risky decisions has been encountered,
it is either integrated or segregated in the evaluation of the expected ou
tcomes of a current decision. Previous research supports an integration pri
nciple (the loss-sensitivity principle) stating that a prior outcome is onl
y added to the expected losses. An experiment employing four groups of 16 u
ndergraduates was conducted with the aim of investigating whether or not a
prior outcome also influences the subjective probabilities of the expected
outcomes. Although the results failed to show that ratings of subjective pr
obability were affected by a prior outcome, the effect of the prior outcome
on the likelihood of gambling was as expected stronger when the probabilit
ies were inexact and therefore possibly more open to subjective influences.
An alternative explanation was proposed which both assumes that the loss-s
ensitivity principle is valid and that prior outcomes affect decision weigh
ts. (C) 1999 Elsevier Science B.V. All rights reserved.