Sources of difficulty in deductive reasoning: The THOG task

The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding.     

行为与脑的关系及其与机体其它属性间的相互作用的研究──心理学研究展望

“二十一世纪的心理学”的论题是当今许多科学家感兴趣的．这种预测是一种想象与现实相结合的尝试。审视过去和现在．心理学未来的雏形的基础可能是行为与脑的关系及其与生命其它属性之间的相互作用。     

Ethnic differences in psychiatric disorders among adolescent substance abusers in treatment

The present study describes the diagnostic profile of over 800 adolescents admitted to residential therapeutic community programs for treatment of drug abuse and related problems. The relationship between race/ethnicity and psychiatric disturbance is examined, and the association among these factors to outcome is investigated. Over 90% of the sample had a DSM-III-R nonsubstance diagnosis. There were significant differences among the race/ethnic groups on attention deficit-hyperactivity and the disruptive behavior and affective disorders. In general, African-American adolescents yielded the lowest rates of disturbance across all categories of disorders. There was no relationship among race/ethnicity, psychiatric disturbance, and 1-year posttreatment outcomes.     

A PRELIMINARY COMPARISON OF REINFORCER ASSESSMENT METHODS FOR CHILDREN WITH ATTENTION DEFICIT HYPERACTIVITY DISORDER

We evaluated the relative treatment utility of a verbal forced-choice questionnaire, child nomination, and direct observation for identifying the most potent reinforcers for children with attention deficit hyperactivity disorder. Results demonstrated that all three methods were more likely to disagree than to agree, that a forced-choice format may enhance verbal reinforcer assessment, and that further development and evaluation of verbal reinforcer-assessment methods are needed.     

Are All Hostility Scales Alike? Factor Structure and Covariation Among Measures of Hostility1

Few studies have examined the correlational and structural relationships between measures of hostility that may predict coronary heart disease. Using data from a population-based study (N= 2,682), we examined the factor structure among the five subscales from Siegel's (1986) Multi-dimensional Anger Inventory, the three subscales from Spielberger et al.'s (1985) anger expression scales, a Cook-Medley (Cook & Madley, 1954) hostility subscale that measures cynicism, and items measuring hostility from four scales that assess Type A behavior. Eight separate factors were identified: hostile anger expression, perceived control over the expression of one's anger, frequency of anger, ease of anger provocation, brooding, hostile outlook, cynicism, and sullenness. These results suggest that the structure of hostility measures is more complex than previous factor analyses have suggested. Our findings point to the dangers in assuming that a factor structure can be generalized beyond the data on which it is based to provide theoretical statements about psychological structure. The new scales appear to be valid because they correlate with demographic variables and indicators of social support in the expected directions.     

Comparing Students From Substance Abusing and Dysfunctional Families: Implications for Counseling

This research compared family role dysfunction, college adjustment, chemical dependence, and family functioning among a sample of 245 college students from three groups: homes in which significant alcohol or other chemical abuse or dependence dysfunction existed; dysfunctional homes in which substance abuse was not a significant problem; and nonabusing, nondysfunctional homes. The results suggest that chemical abuse or dependence in families is associated with slowed adult role assimilation and increased risk for alcohol and other drug abuse among children.     

RUMINATIONS ON RUSE AND RELIGION

Abstract. I am in general agreement with Ruse on most religious and scientific issues but find little justification in his partial return to Christianity. His rejection of the literal interpretation of certain "Jewish myths," once started, can logically end only with the rejection of all the important content of both Old and New Testaments. His recognition that religious establishments have been responsible for much personal stress and many of history's great tragedies is understated.     

Orienting the finger opposition space during prehension movements

Two experiments are reported that examined the act of prehension when subjects were asked to grasp with their thumb and index finger pads an elongated object resting horizontally on a surface and placed at different orientations with respect to the subject. In Experiment 1, the pad opposition preferences were determined for the six angles of orientation examined. For angles of 90 degrees (object parallel to frontal plane) or less, no rotation of the wrist (pronation) was used; for angles 110 degrees or greater, pronation was systematically employed to reorient the finger opposition space. Only one angle, 100 degrees , produced any evidence of ambiguity in how to grasp the object: Approximately 60% of these grasps involved pronation and 40% did not. Using the foregoing grasp preference data, in Experiment 2 we examined the kinematics of the wrist and elbow trajectories during prehension movements directed at an object in different orientations. Movement time, time to peak acceleration, velocity, and deceleration were measured. No kinematic differences were observed when the object orientation either required (110 degrees ) or did not require (80 degrees ) a pronation. By contrast, if the orientation was changed at the onset of the movement, such that an unpredicted pronation had to be introduced to achieve the grasp, kinematics were affected: Movement time was increased, and the time devoted to deceleration was lengthened. These data are interpreted as evidence that when natural prehension occurs, pronation can be included in the motor plan without affecting the movement kinematics. When constraints are imposed on the movement execution as a consequence of a perturbation, however, the introduction of a pronation component requires kinematic rearrangement.