Cognitive dissonance reduction as constraint satisfaction.

A constraint satisfaction neural network model (the consonance model) simulated data from the two major cognitive dissonance paradigms of insufficient justification and free choice. In several cases, the model fit the human data better than did cognitive dissonance theory. Superior fits were due to the inclusion of constraints that were not part of dissonance theory and to the increased precision inherent to this computational approach. Predictions generated by the model for a free choice between undesirable alternatives were confirmed in a new psychological experiment. The success of the consonance model underscores important, unforeseen similarities between what had been formerly regarded as the rather exotic process of dissonance reduction and a variety of other, more mundane psychological processes. Many of these processes can be understood as the progressive application of constraints supplied by beliefs and attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mid Holocene lake level and shoreline behavior during the Nipissing phase of the upper Great Lakes at Alpena, Michigan, USA

The Nipissing phase was the last pre-modern high-water stage of the upper Great Lakes. Represented as either a one- or two-peak highstand, the Nipissing occurred following a long-term lake-level rise. This transgression was primarily an erosional event with only the final stage of the transgression preserved as barriers, spits, and strandplains of beach ridges. South of Alpena, Michigan, mid to late Holocene coastal deposits occur as a strandplain between Devils Lake and Lake Huron. The landward part of this strandplain is a higher elevation platform that formed during the final stage of lake-level rise to the Nipissing peak. The pre-Nipissing shoreline transgressed over Devils Lake lagoonal deposits from 6.4 to 6.1 ka. The first beach ridge formed ~ 6 ka, and then the shoreline advanced toward Lake Huron, producing beach ridges about every 70 years. This depositional regression produced a slightly thickening wedge of sediment during a lake-level rise that formed 20 beach ridges. The rise ended at 4.5 ka at the Nipissing peak. This peak was short-lived, as lake level fell > 4 m during the following 500 years. During this lake-level rise and subsequent fall, the shoreline underwent several forms of shoreline behavior, including erosional transgression, aggradation, depositional transgression, depositional regression, and forced regression. Other upper Great Lakes Nipissing platforms indicate that the lake-level change observed at Alpena of a rapid pre-Nipissing lake-level rise followed by a slower rise to the Nipissing peak, and a post-Nipissing rapid lake-level fall is representative of mid Holocene lake level in the upper Great Lakes.     

Effects of Pressure and pH on the Hydrolysis of Cytosine: Implications for Nucleotide Stability around Deep‐Sea Black Smokers

The relatively low chemical stability of cytosine compared with other nucleobases is a key concern in origin‐of‐life scenarios, but the effect of pressure on the rate of hydrolysis of cytosine to uracil remains unknown. Through in situ NMR spectroscopy measurements, it has been determined that the half‐life of cytosine at 373.15 K decreases from (18.0±0.7) days at ambient pressure (0.1 MPa) to (8.64±0.18) days at high pressure (200 MPa). This yields an activation volume for hydrolysis of (?11.8±0.5) cm³ mol^?1; a decrease that is similar to the molar volume of water (18.0 cm³ mol^?1) and consistent with a tetrahedral 3,3‐hydroxyamine transition‐state/intermediate species. Similar behaviour was also observed for cytidine. At both ambient and high pressures, the half‐life of cytosine decreases significantly as the pH decreases from 7.0 to 6.0. These results provide scant support for the notion that RNA‐based life forms originated in high‐temperature, high‐pressure, acidic environments.     

Cesarean childbirth and psychosocial outcomes: A meta-analysis.

A comprehensive literature review with meta-analysis examines the differences between vaginal and cesarean delivery on 23 psychosocial outcomes of childbirth. The most robust findings suggest that cesarean mothers, compared with mothers who delivered vaginally, expressed less immediate and long-term satisfaction with the birth, were less likely ever to breast-feed, experienced a much longer time to first interaction with their infants, had less positive reactions to them after birth, and interacted less with them at home. Some differences were also found between unplanned and planned cesarean sections; none were found between birthing methods for maternal confidence for infant caretaking soon after birth, maternal anxiety in the hospital and at home, maternal stress at home, maternal return to work, and continuation of breast-feeding once begun. Implications of these findings for theory, research, and childbirth practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An objective methodology for dose distribution analysis

The advent of single aliquot optically stimulated luminescence (OSL) techniques along with parallel equipment advances have made it possible and practical to obtain statistically meaningful quantities of equivalent dose (De) data from individual samples. Now that hundreds of dose determinations can be made for one sample De distributions may be scrutinised, leading to the problem of how to make unbiased comparisons among distributions, and how to decide objectively which dose is representative of the age of the deposit. In this paper, an objective analytical method is presented for treating dose distributions, including a mathematically rigorous means of determining a representative equivalent dose and a statistical definition of its corresponding uncertainty. This analytical method has been applied to Holocene aeolian and fluvial quartz sands from Central Oklahoma. The results are compared to equivalent doses determined via other proposed analytical procedures.     

Effects of fantasy contexts on children's learning and motivation: Making learning more fun.

Two studies examined the effects of embedding instructional materials in relevant fantasy contexts on children's motivation and learning. In Study 1, Ss showed marked preferences for computer-based educational programs that involved fantasy elements. In Study 2, Ss worked with these programs for 5 hrs. One program presented purely abstract problems. Others presented identical problems within fantasy contexts. Some Ss chose among 3 fantasies; others were assigned identical fantasies. Tests on the material occurred before, immediately after, and 2 wks after the experimental sessions. Ss showed significantly greater learning and transfer in the fantasy than in the no-fantasy conditions. Having a choice of fantasies made no difference. Motivational and individualization strategies for enhancing interest and promoting learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling long-term parent outcomes of two universal family-focused preventive interventions: One-year follow-up results.

The present investigation extended prior work by R. Spoth, S. Redmond, and C. Shin (see record 1998-01101-018). These researchers reported findings that 2 universal family-focused preventive intervention programs each had direct effects on a proximal parenting outcome (intervention-targeted parenting behaviors) and indirect effects on 2 global and distal outcomes (parent–child affective quality and general child management) at posttesting. A replication of the previously tested parenting outcome model was conducted with 1-year follow-up data and procedures identical to those used in the earlier study. Results of the present study (N?=?404 families) indicate that statistically significant effects on parenting outcomes were sustained through a 1-year period following the posttest. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The hostile media phenomenon: Biased perception and perceptions of media bias in coverage of the Beirut massacre.

68 pro-Israeli, 27 pro-Arab, and 49 politically neutral undergraduates viewed identical samples of major network TV coverage of the Beirut massacre and rated them as being biased against their side. Results indicate that the hostile media phenomenon appears to involve the operation of 2 separate mechanisms. Ss evaluated the fairness of the media's sample of facts and arguments differently, in light of their own divergent views about the objective merits of each side's case and their corresponding views about the nature of unbiased coverage. Ss also reported different perceptions and recollections about the program content itself; that is, each group reported more negative references to their side than positive ones, and each predicted that the coverage would sway nonpartisans in a hostile direction. Within both partisan groups, furthermore, greater knowledge of the crisis was associated with stronger perceptions of media bias. It is concluded that charges of media bias may reflect more than self-serving attempts to secure preferential treatment. They may result from the operation of basic cognitive and perceptual mechanisms that should prove relevant to perceptions of fairness or objectivity in a wide range of mediation and negotiation contexts. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attitude prototypes as determinants of attitude–behavior consistency.

Hypothesized that individuals determine their attitudes toward a social group by assessing their reactions to an imagined group representative who embodies the defining or central group characteristics—the prototypical group member. When they encounter a specific group member whose characteristics match well those of the "attitude prototype," individuals display attitude–behavior consistency; when the match is poor, they display attitude–behavior inconsistency. This proposition was tested in 2 experiments with 56 undergraduates: Ss completed questionnaires assessing their attitudes toward various groups, and later their behavior toward prototypical and unprototypical individuals of those groups was evaluated. In each experiment, the attitude–behavior relationship was greater in relation to prototypical than to unprototypical group members. Knowledge of an unprototypical group member had little or no effect on attitude prototypes. Rather, the unprototypical group member was dismissed as atypical, leaving the prototype intact to influence future social behavior. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)