Validation of a full body 3-D dynamic linked segment model

In studies related to human movement, linked segment models (LSM's) are often used to quantify forces and torques, generated in body joints. Some LSM's represent only a few body segments. Others, for instance used in studies on the control of whole body movements, include all body segments. As a consequence of the complexity of 3-dimensional (3-D) analyses, most LSM's are restricted to one plane of motion. However, in asymmetric movements this may result in a loss of relevant information. The aim of the current study was to develop and validate a 3-D LSM including all body segments. Braces with markers, attached to all body segments, were used to record the body movements. The validation of the model was accomplished by comparing the measured with the estimated ground reaction force and by comparing the torques at the lumbo-sacral joint that resulted from a bottom-up and a top-down mechanical analysis. For both comparisons, reasonable to good agreement was found. Sources of error that could not be analysed this way, were subjected to an additional sensitivity analysis. It was concluded that the internal validity of the current model is quite satisfactory.     

Cultural specificity of support sources,correlates and contexts: Three studies of African-American and Caucasian youth

Levels and correlates of parental support, peer support, partner support, and/or spiritual support among African American and Caucasian youth were examined in three contexts: adolescent pregnancy (Study 1), first year of college (Study 2), and adolescence and young adulthood (ages 15–29; Study 3). Partially consistent with a cultural specificity perspective, in different contexts different support sources were higher in level and/or more strongly related to adjustment for one ethnic group than the other. Among pregnant adolescents, levels of spiritual support were higher for African Americans than Caucasians; additionally, peer support was positively related to well-being only for African Americans whereas partner support was positively related to well-being only for Caucasians. Among college freshmen, family support was more strongly related to institutional and goal commitment for African Americans than Caucasians; conversely, peer support was more strongly related to institutional and goal commitment among Caucasians. Among 15 to 29-year-olds, levels of parental support and spiritual support were higher among African Americans than Caucasians; additionally, spiritual support was positively related to self-esteem for African Americans but not for Caucasians. Implications and limitations of the research are discussed. The third study was supported by National Institute of Mental Health Grant RO1 MH40963. We thank Monica Greene, Shea Lyda, Wendy Stevenson, and the many undergraduate students who contributed to the three research projects. We also acknowledge the very thoughtful and helpful comments of the anonymous reviewers and the editor, Edison Trickett.     

Comparing Risky Decision Making Under Conditions of Real and Hypothetical Consequences

In a series of three experiments, subjects made risky decisions under conditions of hypothetical or real consequences. Task variations across experiments included: (1) type of risk (monetary gambles or investments of time and effort), (2) within-subject and between-subjects manipulations of consequence condition, and (3) single or multiple decisions. The hypothesis of no difference between choices in real and hypothetical consequence conditions was retained in each experiment. Supplemental analyses ruled out various “artifactual” interpretations of the null results. Discussion focused on conditions in which researchers can and cannot infer decision makers’ actual risk preferences from their responses in laboratory tasks.     

Rationally developed fake-good and fake-bad scales for the Jesness Inventory

Develops two validity scales for the Jesness Inventory using a rational approach: a fake-good scale, Lie (L); and a fake-bad scale, Overt Symptomatology (OS). Effectiveness was assessed using 293 male delinquents classified as fake-good, fake-bad, or honest based on a matched-pair MMPI-A. L was moderately effective in detecting the fake-good set, and OS tentatively effective in detecting the fake-bad set. Both correlated well with their MMPI-A counterparts. Sensitivity, specificity, positive predictive power, negative predictive power, and overall effectiveness data were reported. The L scale and OS scale were related to race but differences were less than 1 raw score point. L was unrelated to age. OS was related to age, with younger children showing more willingness to admit to symptomatology. Age-based modified T-score norms were developed for the newly constructed scales using 1142 male and 360 female delinquents. ages 13–18.     

A short form of the Common Beliefs Survey III

Previous studies have shown that the Common Beliefs Survey III (CBS III) is an irrational beliefs inventory with satisfactory psychometric properties. We extended research on the CBS by examining this 54-item inventory for redundant material, and substantially abbreviated it without compormising its reliability or validity. This article describes the development of the new, 19-item short form (CBS19), convenient for clinical use, that preserves the psychometric properties of the original.     

Consider the source: One step in assessing premise acceptability

Premise acceptability is conceptually connected to presumption. To say that a premise is acceptable just when there is a presumption in its favor is to give a first approximation to this connection. A number of popular principles of presumption suggest that whether there is a presumption for a premise, belief, or claim depends on the sources which vouch for it. Sources consist of internal belief-generating mechanisms and external testimony. Alvin Plantinga's notion of warrant lays down four conditions upon a source for the belief which it generates to be warranted. We argue that there is a presumption for a premise, belief, or claim if and only if there is a presumption of warrant for that premise,belief or claim. This amounts to the thesis that there is a presumption for a belief from a challenger's point of view if and only if there is a presumption from that person's point of view that her cognitive faculties which have generated the belief have been functioning properly, in an appropriate cognitive environment, in accord with a segment of her design plan aimed at the truth, and that these faculties are reliable. In light of our argument for this thesis, we may legitimately claim that one way to determine that there is a presumption for a belief is to determine that there is a presumption of warrant for that belief, and thus that in determining whether there is a presumption for a belief or premise, we may consider the source.     

The effects of organizational frames and problem ambiguity on decision making

This paper investigates how organizational climate and information quantity influences choice of decision making strategies. A simulated company with an organizational climate was manipulated to be either supportive or non-supportive of participative decision making methods. Subjects then solved problems in which information available to make a decision was manipulated. Results indicated that climate has an effect on choice of decision making strategies independent of information quantity. A second study was then conducted to assess how the climate manipulation affected subjects' decision-making. Organizational climate information appears to affect decisions in a manner analogous to Tversky and Kahneman's (1981) decision framing model.The contribution of each author is equal for this paper. The order of authorship was determined by a coin flip. This research was supported by Ohio Board of Regents and University of Akron Faculty Research grants to the second author. Portions of this paper were presented at the 1989 Society of Industrial Organizational Psychology Meetings and the 1991 Association of Management Meetings.