complicated by ambiguous economic, social, and emotional
considerations, and you decide to base your decision entirely on the
following few observations. [To which parent would you award sole
custody of the child?/To which parent would you deny sole custody of
the child?]
Award Deny
Parent A average income
average health
average working hours
reasonable rapport with the child [36%] [45%]
relatively stable social life
Parent B above-average income
very close relationship with the child [64%] [55%]
extremely active social life
lots of work-related travel
minor health problemsParent A, the impoverished option, is quite plain—with no striking positive or
negative features. There are no particularly compelling reasons to award or
deny this parent custody of the child. Parent B, the enriched option, on the
other hand, has good reasons to be awarded custody (a very close relationship
with the child and a good income), but also good reasons to be denied sole
custody (health problems and extensive absences due to travel). To the right of
the options are the percentages of subjects who chose to award and to deny
custody to each of the parents. Parent B is the majority choice both for being
awarded custody of the child and for being denied it, presumably because this
parent provides more compelling reasons both to be awarded as well as denied
child custody. As a result, the child is significantly more likely to end up with
parent B when we ask whom to award custody to than when we contemplate
whom to deny. This discrepancy represents another violation of procedure
invariance, in which two logically equivalent tasks give rise to predictably dif-
ferent choices.
26.6 Choice under Conflict
The rational theory of choice assumes that each alternative has a utility or sub-
jective value for the decision maker. Given a set of options, the decision maker
selects the alternative with the highest value. This principle of value maxi-
mization is routinely assumed in analyzing consumer choice. It implies that
the preference between options cannot be reversed by the addition of new
alternatives. If you prefer salmon to steak, for example, you should not select
steak from a larger menu that includes salmon, unless, of course, other entre ́es
provide some information about the quality of the steak or the salmon. Thus, a
nonpreferred option cannot be made preferred by introducing new alternatives.
Consequently, the ‘‘market share’’ of an option (that is, the proportion of people
614 Eldar Shafir and Amos Tversky