[Jdm-society] Finicky effects

[Bertram F. Malle]

Jon,

You may be correct in this particular case (Lord, Ross, & Lepper),  
but how do we know in general whether something is real & finicky or  
just one data point from a random distribution around d = 0?  My  
earlier example: I bet a lot of people would have said that the actor- 
observer asymmetry in attribution is a real effect and that “failures  
to replicate this effect are of no interest” (because they firmly  
believed in the effect).  I am also sure they would have said that  
“The fact that it happened a couple of times shows that it is real.”   
But if you look at the entire distribution of studies, the effect  
just isn’t there.  I don’t think we should pick out the cases in  
which the results confirmed the hypothesis and say “It’s possible, so  
it’s an effect.”  Unless we can identify the conditions under which a  
real & finicky effect occurs reliably, the effect has not much value  
(theoretical and practical); indeed, it may be the first sign that it  
isn’t an effect.

Bertram



> Let me give a specific example of a finicky effect.  The polarization
> effect reported first by Lord, Ross, and Lepper (JPSP 1979) is very
> important, yet very difficult to replicate.  This is because many
> factors work against it.  It requires a very extreme effect to
> overcome the tendencies to respond to mixed evidence by moving in the
> direction of moderation.
>
> To me, failures to replicate this effect are of no interest.  The fact
> that it happened a couple of times shows that it is real and that
> "biased assimilation" of evidence can sometimes (if rarely) be strong
> enough to overcome the rational forces pulling in the opposite
> direction.
>
> Very likely, such biased assimilation is at work in many conflicts.
> In the real world, we cannot tell.  But knowing that it is possible in
> the laboratory makes us aware of the possibility in the world outside.
>
> Jon
> -- 
> Jonathan Baron, Professor of Psychology, University of Pennsylvania
> Home page: http://www.sas.upenn.edu/~baron
> Editor: Judgment and Decision Making (http://journal.sjdm.org)
> President: Society for Judgment and Decision Making (http:// 
> www.sjdm.org)
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Bertram F. Malle, Ph.D.
Associate Professor of Psychology
Director, Institute of Cognitive and Decision Sciences
1227 University of Oregon
Eugene OR 97403-1227

Phone: (541) 346-0475
Fax: (541) 346-4911
Web: www.uoregon.edu/~bfmalle/