Journal «/ Personality and Social Psychology 1973. Vol. 27, No. 3, 301-310 FUNCTIONAL MEASUREMENT OF SOCIAL VALUES 1 MANUEL LEON, 2 GREGG C. ODEN, ANDNORMAN H. ANDERSON University of California, San Diego Integration theory was applied to moral judgments of groups. Subjects judged badness of groups of criminals, each of whom was guilty of one offense. The data supported the averaging hypothesis of information integration, with much greater weighting of the more serious offenses. A subgroup of subjects carried this tendency to an extreme, basing their judgment on the most serious offense and ignoring the lesser offenses in the group. Functional measurement proce- dure was used to scale the offenses. Results were comparable to the Coombs- Thurstone paired-comparison scales of the same stimuli, though some non- linearity appeared at the extremes, possibly a result of bias in the paired- comparison choice data. Advantages of functional scales for group processes are discussed. This report has a twofold purpose. The first is to study how the individual members of a group determine the overall evaluation of that group. The second is to illustrate a new theory of psychological measurement. The present approach begins from a princi- ple of information integration (Anderson, 1971). Each member of the group is viewed as a piece of information that bears on the overall judgment. The first concern of the theory is the process that governs the integra- tion of these individual pieces of information into an overall judgment. The few directly relevant studies have gen- erally supported the averaging hypothesis: The overall evaluation of the group is an average of the values of the members of that group (e.g., Anderson, Lindner, & Lopes, 1973; Oden & Anderson, 1971; Rosnow & Arms, 1968). However, most previous reports have studied attractiveness of groups to which the subject might belong. The present report considers moral judgments of groups whose members have committed certain social of- fenses. Such judgments are relevant to the formation of cultural and social stereotypes. 1 This study was supported by National Science Foundation Grant GB-21028 and by a grant from the National Institute of Mental Health to the Center for Human Information Processing, University of California, San Diego. The authors wish to thank Michael Birnbaum, Robyn Dawes, and James Shanteau for their helpful comments. 2 Requests for reprints should be sent to Manuel Leon, Department of Psychology, University of Cali- fornia, San Diego, P.O. Box 109, La Jolla, California 92037. This judgment task also allows a compari- son between functional measurement proce- dure, which is employed here, and the tradi- tional method of paired comparisons which was used by Thurstone (1927) and Coombs (1967) to scale these same social offenses. Functional measurement yields eqi^al-interval scales, and it has two potential advantages over paired comparisons: It can be applied at the level of the individual subject, whereas paired comparisons cannot. And it i yields not only the scale value of a group member, but also his weight or importance in the overall judgment. Integration Model The evidence cited above support)? the aver- aging hypothesis for group integration. The judgment of a group of two members would be the weighted average, -(- + Wo + wi + w-2 [1] Here s t and s 2 are the scale values of the two members, w\ and w 2 are their weigjhts in the judgment of the group. The terms \s 0 and w 0 are the value and weight of the initial im- pression, an internal state variable that represents prior expectations or response dispositions. The analysis of the averaging: model is simple when the restriction of equal weighting holds (Anderson, 1971, p. 177). A parallelism prediction then obtains that has been sup- ported in numerous experiments i in other 301