title: Human group choice: discrete-trial and free-operant tests of the ideal free distribution.
abstract: Ideal free distribution theory predicts that foragers will form groups proportional in number to the resources available in alternative resource sites or patches, a phenomenon termed habitat matching. Three experiments tested this prediction with college students in discrete-trial simulations and a free-operant simulation. Sensitivity to differences in programmed reinforcement rates was quantified by using the sensitivity parameter of the generalized matching law (s). The first experiment, replicating prior published experiments, produced a greater degree of undermatching for the initial choice (s = 0.59) compared to final choices (s = 0.86). The second experiment, which extended prior findings by allowing only one choice per trial, produced comparable undermatching (s = 0.82). The third experiment used free-operant procedures more typical of laboratory studies of habitat matching with other species and produced the most undermatching (s = 0.71). The results of these experiments replicated previous results with human groups, supported predictions of the ideal free distribution, and suggested that undermatching represents a systematic deviation from the ideal free distribution. These results are consistent with a melioration account of individual behavior as the basis for group choice.
authors.affiliation: Department of Psychology, University of Wisconsin-Eau Claire, 54702-4004, USA. maddengj@uwec.edu
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Madden
authors.forename: Blaine F
authors.initials: BF
authors.lastname: Peden
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D002755:Choice Behavior; D003163:Competitive Behavior; D005260:Female; D006126:Group Processes; D006801:Humans; D008297:Male; D009042:Motivation; D012055:Reinforcement Schedule; D016008:Statistical Distributions; D013334:Students / Q000523:psychology