Expectancies as mediators in the differential-reward conditional discrimination performance of pigeons

In a series of within-subject experiments employing a two-choice delayed conditional discrimination task, pigeons chose correctly more often when kind of correct choice and kind of reinforcer were perfectly correlated than when uncorrelated. Correct choice behavior fell to chance levels when the correlation was reversed or when it was removed by using only one kind of reinforcer. Implications for mediation theories are discussed, with the conclusion being that, although the possibility that instrumental mediators are present in this situation cannot be dismissed, the overall pattern of results indicates that classical mediators are of principal importance in this type of task.     

The Development of Chemical Language Usage by “Non-traditional” Students: the Interlanguage Analogy

Research in Science Education - Students commonly find specialist scientific language problematic. This study investigated developments in chemical language usage by six non-traditional students...     

Becoming Fathers: Initial Exploration of a Support Program for New Fathers

Emerging fathers experience a variety of stressors, including identity and role transitions, changes in their relationships, and challenges in developing caregiving skills. Increasing expectations for father involvement in childcare are emphasizing the importance of the father role, but social supports for new fathers remain scarce. Nineteen expectant and new fathers participated in a pilot 5-week group intervention aimed at improving stress coping and involvement attitudes using a combination of mindfulness practices and skill-building for parenting and partner communication. We administered surveys pre- and postintervention to assess efficacy in the areas of stress, depressive symptoms, father involvement attitudes, and mindfulness. Within-participant differences were compared across participants as well as examining individual reliable change. Results indicated initial reductions in stress and depressive symptoms and increases in the mindfulness constructs of nonjudgment and nonreactivity. No significant changes were found in father involvement attitudes. Perinatal intervention specific to fathers holds promise as an underexplored avenue for supporting families across the transition to parenthood.     

From Science Studies to Scientific Literacy: A View from the Classroom

The prospective virtues of using history and philosophy of science in science teaching have been pronounced for decades. Recently, a role for nature of science in supporting scientific literacy has become widely institutionalized in curriculum standards internationally. This short review addresses these current needs, highlighting the concrete views of teachers in the classroom, eschewing ideological ideals and abstract theory. A practical perspective highlights further the roles of history and philosophy—and of sociology, too—and even broadens their importance. It also indicates the relevance of a wide range of topics and work in Science Studies now generally absent from science educational discourse. An extensive reference list is provided.     

Stress Reactivity and Self-Recognition

This study examined longitudinally whether early differences in reactivity to stress are related to self-recognition at 18 months of age. Adrenocortical and behavioral to Stress responses to routine inoculation at 2, and 4 months and at 6 and 18 months were obtained. Previous finding indicated a development shift in adrenocortical functioning by 6 months of age that included the emergence of stable individual differences in cortisol response from this point in development. Self-recognition was related to greater cortisol response and less rapid quieting at 6 to 18 months, whereas 2- to 4-month cortisol and quieting response did not differentiate self-recognizers and non-self-recognizators. These findings indicate a role for temperament differences in facilitating the emergence of self-recognition.     

Endogenous technical advance and the stochastic trend in output: A neoclassical approach

In the recent endogenous growth literature, the trend in output is stochastic, while investment in scientific knowledge is treated as analogous to a capital stock. This paper models both research and development (R&D) and disembodied technical advance using neo-classical equations, which specify the equilibrium stocks as a function of prices and output. The elasticity of R&D in the production function, estimated using factor shares, is time-varying and increasing. Returns to scale are increasing in all factors. The most important aspect of the model is that the equilibrium rate of technical advance is not cyclically invariant, but co-moves with output at business cycle frequencies. This allows the production function to behave as a stochastic trend. Growth accounting demonstrates that long-term variations in the rate of productivity growth have been associated mainly with low-frequency fluctuations in the rate of disembodied technical advance, with secondary effects from the stocks of R&D and physical capital. During the high productivity period 1948–1972, technical advance contributed 1.48 percentage points per year to output, with 0.98 accounted for by R&D. The productivity slowdown of the mid-1970s was accounted by a gradual decline in the effect of R&D, and a more abrupt collapse in disembodied technology. The subsequent productivity revival was associated with two accelerations in disembodied technical advance, the first beginning in the early 1980s, and the second in the mid-1990s. The production function is simulated in a small econometric model. Model simulations find that exogenous shocks to the inflation rate generate significant variations in growth by inducing fluctuations in disembodied technology.