Weighing Pros and Cons

The study of Shafir (1993):

Procedure invariance means that two logically equivalent tasks should yield the same outcome in a judgment or decision task.

For example, if a jury members are asked to whom of to parents to award child sole-custody, their decision should be same as when asked to whom to deny custody.

Shafir (1993) gave his participants the following problem:

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Weighing Pros and Cons

Imagine that you serve on the jury of an only-

child sole-custody case following a relatively

messy divorce. The facts of the case are

complicated by ambiguous economic, social,

and emotional considerations, and you decide

to base your decision entirely on the following

few observations.

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Weighing Pros and Cons

One group of respondents was asked „To which parent would you award sole custody of the child?“The other group was asked: „To which parent would you deny sole custody of the child?“

Parent A: average incomeaverage healthaverage working hoursreasonable rapport with childrelatively stable social life

Parent B: above-average incomeminor health problemsmany working hoursexcellent rapport with childhighly active social life

36%

64%

Award

55%

45%

Deny

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Two logically equivalent tasks yielded different

choices. If asked to award child custody,

respondents based their decisions on salient

positive features of the parent; if asked to deny

child custody, respondents based their decisions

on salient negative features of the parent. Parent

B had both salient positive and negative features

and was therefore both awarded and denied

child custody, depending on the question.

Weighing Pros and Cons

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Weighing Pros and Cons

This violates description invariance or procedure invariance,

like in studies on compatibility effects (see Slovic &

Lichtenstein, 1983; Tversky, Slovic, and Kahneman, 1990),

and relative prominence (Kahneman & Ritov, 1993;

Tversky, Sattah, & Slovic, 1988).

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This is a typical example of a positive test strategy in that

people search information that elicits positive responses;

these are positive traits if asked to award child custody

and negative traits if asked to deny child custody.

Such mechanisms may also play for job decisions: If there are very few

open positions, the committee may first ask which applicants to exclude

from the list for interviews; according to the logic demonstrated by Shafir,

those are excluded with salient negative features, even if these are

outweighed by salient positive features.

If there are many open positions, the committee may ask first whom

they want include for sure into the list. This favors people with salient

positive features, even if they are outweighed by salient negative

features.

Again, the procedure plays a crucial role in decision making.

Weighing Pros and Cons

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