Racial differences in intelligence: The importance of the executive system

The race-IQ controversy arose at a time when psychometric views of intelligence dominated. Little attention was paid to more process-oriented models in spite of the fact they provide alternative perspectives on the causes of individual differences in problem-solving. We hypothesized that much of the IQ spread commonly observed between black and white children can be attributed to differences in components of their executive systems, including the knowledge base, control processes, and metacognitive states. To test this possibility, black and white children who differed significantly on fluid and crystallized intelligence were tested on multiple tasks reflecting components of the executive systems as well as on perceptual efficiency tasks. Striking group differences were observed in metamemory, stragegy use, and general knowledge, but few reliable differences were found in perceptual efficiency. Regression analyses showed that different factors predicted fluid and crystallized intelligence, with metamemory predicting the latter but not the former. An implication of these findings has potential educational significance: training directed at executive skills, introduce at an early age, might elevate learning and problem-solving skills in black children, thereby reducing racial differences in crystallized intelligence.     

Logical structuralism and Benacerraf’s problem

There are two general questions which many views in the philosophy of mathematics can be seen as addressing: what are mathematical objects, and how do we have knowledge of them? Naturally, the answers given to these questions are linked, since whatever account we give of how we have knowledge of mathematical objects surely has to take into account what sorts of things we claim they are; conversely, whatever account we give of the nature of mathematical objects must be accompanied by a corresponding account of how it is that we acquire knowledge of those objects. The connection between these problems results in what is often called “Benacerraf’s Problem”, which is a dilemma that many philosophical views about mathematical objects face. It will be my goal here to present a view, attributed to Richard Dedekind, which approaches the initial questions in a different way than many other philosophical views do, and in doing so, avoids the dilemma given by Benacerraf’s problem.     

Dynamic epistemic logic with branching temporal structures

van Bentham et al. (Merging frameworks for interaction: DEL and ETL, 2007) provides a framework for generating the models of Epistemic Temporal Logic (ETL: Fagin et al., Reasoning about knowledge, 1995; Parikh and Ramanujam, Journal of Logic, Language, and Information, 2003) from the models of Dynamic Epistemic Logic (DEL: Baltag et al., in: Gilboa (ed.) Tark 1998, 1998; Gerbrandy, Bisimulations on Planet Kripke, 1999). We consider the logic TDEL on the merged semantic framework, and its extension with the labeled past-operator “P _ϵ” (“The event ϵ has happened before which. . .”). To axiomatize the extension, we introduce a method for transforming a given model into a normal form in a suitable sense. These logics suggest further applications of DEL in the theory of agency, the theory of learning, etc.     

Testing Theoretical Explanations of Intention to Seek Care for a Breast Cancer Symptom1

The purpose of this research was to test theoretical explanations of intention to seek care promptly for a breast cancer symptom. Psychosocial variables (affect, expectations, values, and norms), habit, and facilitating conditions (e.g., insurance) regarding care seeking were proposed to influence intention to seek care promptly. Whether psychosocial variables and habit influenced intention directly or in interaction with facilitating conditions remained unclear. Other variables (i.e., clinical and demographic) were proposed to influence intention by mediation through the theoretical variables. Community-dwelling women without history of breast cancer (N= 99) responded to a questionnaire to assess study variables. In a hierarchical set regression, intention was first regressed on psychosocial variables, habit, and full insurance coverage for care, then on terms representing interactions of insurance coverage with psychosocial variables and habit, and lastly on clinical and demographic variables. Findings revealed that (a) anxiety (measure of affect), utility, (the product of expectations and values), and habit were related to intention, (b) having full insurance coverage did not moderate these relationships, and (c) after controlling for theoretical variables, family history of breast cancer was related inversely to intention. Implications for theory, research, and practice are delineated.     

Does recognition of single words predict recognition of two?

Participants studied a list of words, presented 1 at a time. When they were tested on pairs of words and asked to indicate whether both had occurred in the list, they gave more positive responses than would be expected on the basis of results from participants tested 1 word at a time. When participants were asked whether either member of a test pair had been shown on the study list, they gave positive responses less often than expected. When participants were asked to indicate how many words in a test pair came from the study list, they answered "2" more often and "1" less often than would be expected on the basis of results from single-item recognition. Accuracy was not affected by testing items in pairs.     

Gender similarities and differences in children's social behavior: finding personality in contextualized patterns of adaptation

This research examined how a contextualist approach to personality can reveal social interactional patterns that are obscured by gender comparisons of overall behavior rates. For some behaviors (verbal aggression), girls and boys differed both in their responses to social events and in how often they encountered them, yet they did not differ in overall behavior rates. For other behaviors (prosocial), gender differences in overall rates were observed, yet girls and boys differed more in their social environments than in their responses to events. The results question the assumption that meaningful personality differences must be manifested in overall act trends and illustrate how gender differences in personality can be conceptualized as patterns of social adaptation that are complex and context specific.     

A single bout of resistance exercise can enhance episodic memory performance

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise.     

Sequential responding and planning in capuchin monkeys (Cebus apella)

Previous experiments have assessed planning during sequential responding to computer generated stimuli by Old World nonhuman primates including chimpanzees and rhesus macaques. However, no such assessment has been made with a New World primate species. Capuchin monkeys (Cebus apella) are an interesting test case for assessing the distribution of cognitive processes in the Order Primates because they sometimes show proficiency in tasks also mastered by apes and Old World monkeys, but in other cases fail to match the proficiency of those other species. In two experiments, eight capuchin monkeys selected five arbitrary stimuli in distinct locations on a computer monitor in a learned sequence. In Experiment 1, shift trials occurred in which the second and third stimuli were transposed when the first stimulus was selected by the animal. In Experiment 2, mask trials occurred in which all remaining stimuli were masked after the monkey selected the first stimulus. Monkeys made more mistakes on trials in which the locations of the second and third stimuli were interchanged than on trials in which locations were not interchanged, suggesting they had already planned to select a location that no longer contained the correct stimulus. When mask trials occurred, monkeys performed at levels significantly better than chance, but their performance exceeded chance levels only for the first and the second selections on a trial. These data indicate that capuchin monkeys performed very similarly to chimpanzees and rhesus monkeys and appeared to plan their selection sequences during the computerized task, but only to a limited degree.