A cluster analysis of text message users based on their demand for text messaging: A behavioral economic approach

The goal of this study was to determine whether cluster analysis could be used to identify distinct subgroups of text message users based on behavioral economic indices of demand for text messaging. Cluster analysis is an analytic technique that attempts to categorize cases based on similarities across selected variables. Participants completed a questionnaire about mobile phone usage and a hypothetical texting demand task in which they indicated their likelihood of paying an extra charge to continue to send text messages. A hierarchical cluster analysis was conducted on behavioral economic indices, such as demand intensity, demand elasticity, breakpoint, and the maximum expenditure. With the cluster analysis, we identified 3 subgroups of text message users. The groups were characterized by (a) high intensity and low elasticity, (b) high intensity and medium elasticity, and (c) low intensity and high elasticity. In a demonstration of convergent validity, there were statistically significant and conceptually meaningful differences across the subgroups in various measures of mobile phone use and text messaging. Cluster analysis is a useful tool for identifying and profiling distinct, practically meaningful groups based on behavioral indices and could provide a framework for targeting interventions more efficiently.     

Redeeming Apartheid's Legacy: Collective Guilt, Political Ideology, and Compensation

This paper reports two studies among white South African students on feelings of collective guilt about apartheid and attitudes to affirmative action. Study 1 reports on 21 in-depth interviews, Study 2 on results from 180 survey questionnaires. Substantial proportions of the participants in both studies displayed feelings of collective guilt. Among participants in both studies who identified strongly with white South Africans, some displayed strong feelings of collective guilt while others displayed no such feelings. Our survey data suggest that political ideology functions as a moderator. Strong feelings of guilt were found among students who identified strongly with white South Africans and defined themselves as liberals. If they defined themselves as conservatives then no feelings of collective guilt were observed. Strong feelings of collective guilt were accompanied by positive attitudes toward affirmative action. The influence of political ideology on attitudes toward affirmative action was mediated by collective guilt.     

Toward a comprehensive test battery for face cognition: Assessment of the tasks

Despite the importance of face recognition in everyday life and frequent complaints about its failure, there is no comprehensive test battery for this ability. As a first step in constructing such a battery, we present 18 tasks aimed at measuring face perception, face learning, face recognition, and the recognition of facially expressed emotions. A sample of 153 healthy young adults completed all tasks. In general, reaction time measures showed high estimates of internal consistency; tasks focused on performance accuracy yielded reliabilities that were somewhat lower, yet high enough to support their use in a battery of face cognition measures. Some of the tasks allowed computation of established experimental effects in a within-subjects design, such as the part-whole effect. Most of these experimental effects were confirmed in our large sample, and valuable effect size estimates were obtained. However, in many cases these difference measures showed poor estimates of internal consistency.     

Satisficing in financial decision making — a theoretical and experimental approach to bounded rationality

We apply the theoretical construct of bounded rationality to an investment game, allowing participants to invest their monetary endowment in riskless bonds and risky assets. In our experiment, we elicit aspiration levels from participants: one captures a subsistence threshold, the other a success threshold. Participants can be classified according to these aspirations and the corresponding investment behavior. We differentiate between potential and actual satisficing. By presupposing specific cardinal utility functions, we also relate the bounded rationality approach to the traditional rational choice model.     

Emotions in Go/NoGo conflicts

On the basis of current emotion theories and functional and neurophysiological ties between the processing of conflicts and errors on the one hand and errors and emotions on the other hand we predicted that conflicts between prepotent Go responses and occasional NoGo trials in the Go/NoGo task would induce emotions. Skin conductance responses (SCRs), corrugator muscle activity, and startle blink responses were measured in three experiments requiring speeded Go responses intermixed with NoGo trials of different relative probability and in a choice reaction experiment serving as a control. NoGo trials affected several of these emotion-sensitive indicators as SCRs and startle blinks were reduced whereas corrugator activity was prolonged as compared to Go trials. From the pattern of findings we suggest that NoGo conflicts are not aversive. Instead, they appear to be appraised as obstructive for the response goal and as less action relevant than Go trials.     

I recognize your face, but I can't remember your name: A question of expertise?

In four experiments on the identification of familiar faces we reassessed a robust performance pattern—namely, the temporal advantage for retrieving biographical facts as compared to recalling proper names, which has been interpreted as reflecting a serial ordering of the access to semantic and name information. Evidence for recent parallel accounts had been provided by Scanlan and Johnston (1997) who reported an advantage for name retrieval in children. Here we replicated the findings of Scanlan and Johnston but also showed that the naming advantage disappears, and performance is very similar to that of adults when stimuli and tasks are used that are familiar to children. Conversely, we also demonstrated an advantage for name retrieval in adults when highly unfamiliar semantic facts were associated with the faces. Together these findings suggest that there is no fundamental difference in the cognitive architectures of children and adults. The experiments indicate that the relative speed of naming and semantic fact retrieval depends on the expertise with the semantic facts to be retrieved. Implications for models of face identification and naming are discussed.