Social Indispensability or Social Comparison: The Why and When of Motivation Gains of Inferior Group Members1

In 2 experimental studies, social indispensability and upward social comparison were contrasted as potential triggers of motivation gains of inferior group members. Using a cognitive task in a computer‐supported environment, individual work was compared with conditions that enabled upward comparison only (coaction), or both upward comparison and social indispensability (conjunctive task). Moreover, working conditions (face‐to‐face vs. anonymous) and partner‐related performance feedback (contemporaneously vs. post‐task) were manipulated as potential moderators. Results revealed motivation gains only when partner feedback was contemporaneously available. In this case, upward‐comparison effects could be demonstrated during coaction. However, when participants' contribution determined a group outcome, their motivation was additionally increased, demonstrating social indispensability effects. Finally, motivation gains were generally higher during face‐to‐face compared to anonymous work.     

The event reconstruction method: An efficient measure of experience‐based job satisfaction

Job satisfaction is predominantly measured as global attitudinal judgment which requires employees to summarize their experiences across different job situations. In contrast, experience‐based measures assess momentary thoughts and feelings of the employees in specific job situations. This paper introduces the event reconstruction method (ERM) as an efficient measure of experience‐based job satisfaction that is less invasive and less time consuming compared with traditional experience sampling methods. An initial validation study is reported with N=193 employees from a German wholesale company. As expected, job satisfaction measured with the ERM was different from attitudinal job satisfaction. Also, consistent with expectations, experience‐based job satisfaction was a better predictor of self‐reported helping behaviour, whereas attitudinal job satisfaction was a better predictor of turnover intentions. Finally, comparing the ERM results with the results of a similar study using a traditional experience sampling method ( Fisher, 2002 ) revealed very similar patterns.     

Dreaming of white bears: the return of the suppressed at sleep onset

The present study examined the effects of thought suppression on sleep-onset mentation. It was hypothesized that the decrease of attentional control in the transition to sleep would lead to a rebound of a suppressed thought in hypnagogic mentation. Twenty-four young adults spent two consecutive nights in a sleep laboratory. Half of the participants were instructed to suppress a target thought, whereas the other half freely thought of anything at all. To assess target thought frequency, three different measures were used in the wake state and mentation reports were repeatedly prompted by a computer at sleep onset. In support of the hypothesis, results revealed a reversal of target thought frequency at sleep onset: Participants instructed to suppress reported fewer target thoughts than did controls before falling asleep, but more target thoughts afterwards.     

A hierarchical approach for fitting curves to response time measurements

Understanding how response time (RT) changes with manipulations has been critical in distinguishing among theories in cognition. It is well known that aggregating data distorts functional relationships (e.g., Estes, 1956). Less well appreciated is a second pitfall: Minimizing squared errors (i.e., OLS regression) also distorts estimated functional forms with RT data. We discuss three properties of RT that should be modeled for accurate analysis and, on the basis of these three properties, provide a hierarchical Weibull regression model for regressing RT onto covariates. Hierarchical regression model analysis of lexical decision task data reveals that RT decreases as a power function of word frequency with the scale of RT decreasing 11% for every doubling of word frequency. A detailed discussion of the model and analysis techniques are presented as archived materials and may be downloaded from www.psychonomic.org/archive.     

Unrestricted composition and restricted quantification

Many of those who accept the universalist thesis that mereological composition is unrestricted also maintain that the folk typically restrict their quantifiers in such a way as to exclude strange fusions when they say things that appear to conflict with universalism. Despite its prima facie implausibility, there are powerful arguments for universalism. By contrast, there is remarkably little evidence for the thesis that strange fusions are excluded from the ordinary domain of quantification. Furthermore, this reconciliatory strategy seems hopeless when applied to the more fundamental conflict between universalism and the intuitions that tell against it.

The overlap model: a model of letter position coding

Recent research has shown that letter identity and letter position are not integral perceptual dimensions (e.g., jugde primes judge in word-recognition experiments). Most comprehensive computational models of visual word recognition (e.g., the interactive activation model, J. L. McClelland & D. E. Rumelhart, 1981, and its successors) assume that the position of each letter within a word is perfectly encoded. Thus, these models are unable to explain the presence of effects of letter transposition (trial-trail), letter migration (beard-bread), repeated letters (moose-mouse), or subset/superset effects (faulty-faculty). The authors extend R. Ratcliff's (1981) theory of order relations for encoding of letter positions and show that the model can successfully deal with these effects. The basic assumption is that letters in the visual stimulus have distributions over positions so that the representation of one letter will extend into adjacent letter positions. To test the model, the authors conducted a series of forced-choice perceptual identification experiments. The overlap model produced very good fits to the empirical data, and even a simplified 2-parameter model was capable of producing fits for 104 observed data points with a correlation coefficient of .91.     

A practical method for analyzing factorial designs with heteroscedastic data

The Type I error rates and powers of three recent tests for analyzing nonorthogonal factorial designs under departures from the assumptions of homogeneity and normality were evaluated using Monte Carlo simulation. Specifically, this work compared the performance of the modified Brown-Forsythe procedure, the generalization of Box's method proposed by Brunner, Dette, and Munk, and the mixed-model procedure adjusted by the Kenward-Roger solution available in the SAS statistical package. With regard to robustness, the three approaches adequately controlled Type I error when the data were generated from symmetric distributions; however, this study's results indicate that, when the data were extracted from asymmetric distributions, the modified Brown-Forsythe approach controlled the Type I error slightly better than the other procedures. With regard to sensitivity, the higher power rates were obtained when the analyses were done with the MIXED procedure of the SAS program. Furthermore, results also identified that, when the data were generated from symmetric distributions, little power was sacrificed by using the generalization of Box's method in place of the modified Brown-Forsythe procedure.     

On the Relationships between Sum Score Based Estimation and Joint Maximum Likelihood Estimation

This paper analyzes the sum score based (SSB) formulation of the Rasch model, where items and sum scores of persons are considered as factors in a logit model. After reviewing the evolution leading to the equality between their maximum likelihood estimates, the SSB model is then discussed from the point of view of pseudo-likelihood and of misspecified models. This is then employed to provide new insights into the origin of the known inconsistency of the difficulty parameter estimates in the Rasch model. The main results consist of exact relationships between the estimated standard errors for both models; and, for the ability parameters, an upper bound for the estimated standard errors of the Rasch model in terms of those for the SSB model, which are more easily available. The authors acknowledge partial financial support from the FONDECYT Project No. 1060722 from the Chilean Government, and the BIL05/03 grant to P. De Boeck, E. Lesaffre and G. Molenberghs (Flanders) for a collaboration with G. del Pino, E. San Martín, F. Quintana and J. Manzi (Chile).     

Harbour seals (<Emphasis Type="Italic">Phoca vitulina</Emphasis>) can steer by the stars

Offshore orientation in marine mammals is still a mystery. For visual orientation during night-time foraging and travelling in the open seas, seals cannot rely on distant terrestrial landmarks, and thus might use celestial cues as repeatedly shown for nocturnally migrating birds. Although seals detect enough stars to probably allow for astronavigation, it was unclear whether they can orient by the night sky. The widely accepted cognitive mechanism for bird night-time orientation by celestial cues is a time-independent star compass with learned geometrical star configurations used to pinpoint north as the rotational centre of the starry sky while there is no conclusive evidence for a time-compensated star compass or true star navigation. Here, we present results for two harbour seals orienting in a custom made swimming planetarium. Both seals learned to highly accurately identify a lodestar out of a pseudo-randomly oriented, realistic projection of the northern hemisphere night sky. Providing the first evidence for star orientation capability in a marine mammal, our seals’ outstanding directional precision would allow them to steer by following lodestars of learned star courses, a celestial orientation mechanism that has been known to be used by Polynesian navigators but has not been considered for animals yet.