Learning and transfer from a simple dynamic system

The amount of learning gained from being assisted in completing the task of bringing a predator-prey system into equilibrium by controlling the predator population was investigated. Learning was explored both by post-task questioning and by testing for transfer to another predator-prey task. Participants were 28 undergraduate psychology students, all female. They were randomly and evenly split into an experiment group that was subjected to a learning session with the first task before being tested in the second task, and a control group that only performed the second task. What was most needed in the first task was help in sticking to analytically derived conclusions by resisting "common sense" responses. There was a significant transfer effect on performance to the second task, stemming from learning shown by half the participants in the experiment group. The other half showed hardly any learning. Learning in about half the subjects has proven a stable finding.     

Infants learn phonotactic regularities from brief auditory experience

Two experiments investigated whether novel phonotactic regularities, not present in English, could be acquired by 16.5-month-old infants from brief auditory experience. Subjects listened to consonant-vowel-consonant syllables in which particular consonants were artificially restricted to either initial or final position (e.g. /baep/ not /paeb/). In a later head-turn preference test, infants listened longer to new syllables that violated the experimental phonotactic constraints than to new syllables that honored them. Thus, infants rapidly learned phonotactic regularities from brief auditory experience and extended them to unstudied syllables, documenting the sensitivity of the infant's language processing system to abstractions over linguistic experience.     

Measuring transactive memory systems in the field: scale development and validation

This study describes the development and validity testing of a field measure of transactive memory systems. Transactive memory systems are especially important for teams designed to leverage members' expertise, but field research has lagged because there are no adequate measures of the construct. The author developed and tested a 15-item scale in a laboratory sample of 124 teams, a field sample of 64 Master of Business Administration consulting teams, and a field sample of 27 teams from technology companies. Results from the present study demonstrate that the scale is internally consistent, related to alternative measures and hypothesized causes and effects, and unrelated to theoretically distinct constructs, providing evidence of convergent, criterion-related, and discriminant validity. Suggestions for improving the scale, future validity testing, and possible boundary conditions are discussed.     

Hypnosis and clinical pain

Hypnosis has been demonstrated to reduce analogue pain, and studies on the mechanisms of laboratory pain reduction have provided useful applications to clinical populations. Studies showing central nervous system activity during hypnotic procedures offer preliminary information concerning possible physiological mechanisms of hypnotic analgesia. Randomized controlled studies with clinical populations indicate that hypnosis has a reliable and significant impact on acute procedural pain and chronic pain conditions. Methodological issues of this body of research are discussed, as are methods to better integrate hypnosis into comprehensive pain treatment.     

Ecological Factors Impacting Provider Attitudes Towards Human Service Delivery Reform

Although reform efforts are substantially altering the structural operations and guiding ideological framework of the human service delivery system, little empirical work has been done to systematically examine these transformations. This study examines providers' attitudes regarding two reform elements that are being widely implemented: an increased emphasis on inter-agency collaboration and a shift from a medical model service delivery philosophy, that focuses on client deficits, to one that emphasizes consumer strengths. Through survey data collected from 186 providers from 32 human service agencies in one county, the relationship between providers' perceptions of contextual support for human service delivery reform and providers' attitudes towards these initiatives is explored. The findings from this study support the importance of attending to the ecology in which we initiate system reform efforts. For both reform elements, working within contexts that are perceived as providing ideological and functional support for change was associated with positive provider attitudes towards those changes. Staffs' perceptions of the external environment played the most critical role in shaping staff attitudes. Interestingly, unique aspects of providers' work environments were related to positive attitudes towards the two different reforms. The implications of these findings for the success of human service delivery reform are discussed.     

Empathy, Expectations, and Situational Preferences: Personality Influences on the Decision to Participate in Volunteer Helping Behaviors

Although considerable evidence indicates that dispositional empathy is associated with the degree of help that observers will offer needy targets, little is known about the effect of empathy on one's initial willingness to enter situations in which such needy targets might be found. Three studies were conducted to evaluate two related propositions: (1) that dispositional empathy influences such situational preferences, and (2) that this influence is mediated by the expectancies one holds regarding the emotions likely to occur in those situations. Using hypothetical judgments, Study 1 found support for both propositions. Study 2, in which participants believed that their responses actually committed them to encountering needy targets, provided further support for the model, as did Study 3, which examined the experiences of actual community volunteers. The theoretical and practical implications of these findings are discussed.     

Relation of Age of Onset to the Type and Severity of Child and Adolescent Conduct Problems

In a cross-sectional household sample of 9-through 17-year-old youths from 4 U.S. communities, youths with earlier ages of onset of conduct problems engaged in more conduct problems than youths with later ages of onset when current age and gender were controlled. Specifically, youths with earlier ages of onset were more likely to engage in several types of physical aggression, frequent lying, theft, and vandalism and were less likely to engage in only truancy. There also was an inverse relation between age of onset and level of functional impairment, mental health service use, and meeting diagnostic criteria for conduct disorder, attention-deficit hyperactivity disorder, and oppositional defiant disorder. Within the limits of cross-sectional data, these results support the hypothesis that key aspects of the heterogeneity of conduct problems among youths are related to the age of onset of conduct problems.