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Abstract:
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Previous research has shown that causal attributions can be made from patterns of covariation (Cheng , 1997 ) . While the study of how humans learn contingencies goes back decades (e .g . , Ward & Jenkins , 1965 ) , cue interaction effects , involving covariations with two or more cues , have taken on particular importance (e .g . , Shanks , 1985 ) , due to their rich potential for theoretical insights . One such effect is causal discounting (Goedert & Spellman , 2005 ) : People believe a cue is less contingent if they learned about it in the presence of a more contingent cue .
Using a new method for investigating covariation detection , the steamed -trial technique (Allen et al . , 2008 ) , Art Markman , Kelly Goedert and I (Laux et al . , 2010 ) have established that differences in bias underlie causal discounting . We argued that this implies discounting is an effect of a process employed to make causal judgments after learning has occurred . Analyses of how different theories account for discounting , especially simulations of associative models , establishes that this is not necessarily correct ; several learning models can reproduce our data . However , model and data explorations show that the key feature of those data is that they track relative , not absolute , magnitudes .
My dissertation extends this work establishing the plausibility of a comparative judgment process as the locus of causal discounting . I replicate the finding that responding tracks relative magnitudes . By conducting experiments that parametrically manipulate the contingency of the alternative cue (and thereby the relative contingency of the cues ) , I show that causal discounting is due to responding to contingencies as a linear function of their relative magnitude . I further verify that discounting manifests identically in response to contingencies presented via summary tables . Because summary tables do not afford the series of experiences necessary to build an association , this enhances the credibility of the theory that discounting is due to a shared process employed subsequent to learning—namely , a judgment process . These investigations reveal that discounting is not a cue interaction effect at all , but rather is a manifestation of a fundamental aspect of the systems that subserve covariation detection . |