Pregrouping aggression and defense scores influences alcohol consumption for dominant and subordinate rats in visible burrow systems

Five male/two female rat colonies were established in visible burrow systems, with males selected for pregrouping attack scores and also evaluated in open field and cat odor tests. Dominant-subordinate pregrouping attack differences suggested that the males becoming dominant are those showing more persistent and higher level attack. For six colonies showing dominant-subordinate behavioral differences, pregrouping defense tests failed to predict subordinate status. However, pregrouping defense scores were reliably correlated with subordinate pre-postgrouping change scores for voluntary ethanol consumption. Subordinates showed higher ranked ethanol consumption than dominants, but these groups were not different on pregrouping ethanol consumption. Subordinate postgrouping ethanol consumption was positively correlated with pregrouping attack toward an adult intruder, consonant with previous findings that highly aggressive subordinates are the targets of more intense attack by dominants. These results provide further support for a view that subordination stress increases voluntary ethanol consumption in male rats and suggest some additional individual differences factors that may be involved in increased ethanol consumption for male subordinates. © 1992 Wiley-Liss, Inc.     

When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.     

The Participation and Motivations of Grant Peer Reviewers: A Comprehensive Survey

Science and Engineering Ethics - Scientific peer reviewers play an integral role in the grant selection process, yet very little has been reported on the levels of participation or the motivations...     

Statistical learning of multiple speech streams: A challenge for monolingual infants

Language acquisition depends on the ability to detect and track the distributional properties of speech. Successful acquisition also necessitates detecting changes in those properties, which can occur when the learner encounters different speakers, topics, dialects, or languages. When encountering multiple speech streams with different underlying statistics but overlapping features, how do infants keep track of the properties of each speech stream separately? In four experiments, we tested whether 8‐month‐old monolingual infants (N = 144) can track the underlying statistics of two artificial speech streams that share a portion of their syllables. We first presented each stream individually. We then presented the two speech streams in sequence, without contextual cues signaling the different speech streams, and subsequently added pitch and accent cues to help learners track each stream separately. The results reveal that monolingual infants experience difficulty tracking the statistical regularities in two speech streams presented sequentially, even when provided with contextual cues intended to facilitate separation of the speech streams. We discuss the implications of our findings for understanding how infants learn and separate the input when confronted with multiple statistical structures.     

Framing and Group Decision-Making: Do Cognitive Changes Parallel Preference Changes?

Subjects had their initial frames of reference concerning a decision problem (Asian Disease problem; Tversky & Kahneman, 1981, Science,211, 453–458) manipulated in order to compose four-person groups containing members with different frames of reference. Three different group compositions (number of members with "gain-oriented" vs "loss-oriented" frames) were used: three gain-oriented and one loss oriented (3–1), two gain-oriented and two loss-oriented (2–2), and one gain-oriented and three loss-oriented (1–3). Results indicated a postgroup discussion choice shift toward the risk alternative in the 2–2 and the 1–3 composition conditions. However, changes in members′ frames of reference were unrelated to preference changes. Group composition also affected group decision processes. Implications for future theory and research in small group decision-making are discussed.     

Mediating factors in chick social pecking: II. effects of exposure to movement

Unfamiliarity with movement may lead isolated chicks to respond aggressively when tested with live, moving conspecifics. This hypothesis was tested by comparing the number and locus of pecks by isolated chicks to a stationary or moving model of a chick, and to a live chick. In a second test of the hypothesis chicks that viewed a moving object during isolation and chicks isolated without movement were tested with a live con-specific and their number and locus of pecks were compared. Neither experiment supported the hypothesis. Movement alone failed to excite aggressive pecks and prior experience with movement failed to suppress aggressive pecks. In the first experiment imlated chicks treated the live testmate more aggressively than the moving or stationary model. In the second experiment aggressive pecking of chicks was unaffected by prior experience with movement, These fmdmgs do not support the hypothesis that movement excites aggression in isolated chicks. Nonetheless the results focus attention on the generally neglected problem of emotional and motivational states produced by isolation.     

The convergent and discriminant validity of subjective fit perceptions

This study examined whether employees develop perceptions about 3 different types of fit: person-organization fit, needs-supplies fit, and demands-abilities fit. Confirmatory factor analyses of data from 2 different samples strongly suggested that employees differentiate between these 3 types of fit. Furthermore, results from a longitudinal design of 187 managers supported both the convergent and discriminant validity of the different types of fit perceptions. Specifically, person-organization fit perceptions were related to organization-focused outcomes (e.g., organizational identification, citizenship behaviors, turnover decisions), whereas needs-supplies fit perceptions were related to job- and career-focused outcomes (e.g., job satisfaction, career satisfaction, occupational commitment). Although demands-abilities fit perceptions emerged as a distinct construct, they were not related to hypothesized outcomes (e.g., job performance, raises).     

Automaticity and eyewitness accuracy: a 10- to 12-second rule for distinguishing accurate from inaccurate positive identifications

Eyewitness researchers have shown that witnesses accurately choosing the culprit out of a lineup reach their decisions more quickly than those erroneously choosing an innocent individual. However, this research is silent regarding how quickly or slowly witnesses must be, in absolute terms, to indicate that they are accurate or inaccurate. Across 4 studies, the authors discovered that a time boundary of roughly 10 to 12 s best differentiated accurate from inaccurate positive identifications. Witnesses making their identification faster than 10 to 12 s were nearly 90% accurate; those taking longer were roughly 50% accurate. This finding is consistent with previous research showing that accurate witnesses are more likely than inaccurate witnesses to reach their decisions automatically, that is, quickly, without conscious thought or effort.     

Molecular analyses of the principal components of response strength

Killeen and Hall (2001) showed that a common factor called strength underlies the key dependent variables of response probability, latency, and rate, and that overall response rate is a good predictor of strength. In a search for the mechanisms that underlie those correlations, this article shows that (a) the probability of responding on a trial is a two-state Markov process; (b) latency and rate of responding can be described in terms of the probability and period of stochastic machines called clocked Bernoulli modules, and (c) one such machine, the refractory Poisson process, provides a functional relation between the probability of observing a response during any epoch and the rate of responding. This relation is one of proportionality at low rates and curvilinearity at higher rates.