The importance of differentiation in young children’s acquisition of expertise

In a short-term longitudinal study, stories told about novel creatures conveyed information varying in its capability for differentiating. Depending on the context, a bodily feature could be functionally undifferentiated (FUF), meaning that its subtypes (e.g., eyes of two forms) shared a generic function (“seeing”), or functionally differentiated (FDF), meaning that each subtype’s function was unique to it (e.g., only a “hooded eye” could “see in a sandstorm”). 5- to 6-year-olds who heard 8 stories, but not those who heard only 4, cited FDFs more than FUFs in a pair-justification test of judged similarity; and their delayed recall of specific story events was greater when FDFs rather than FUFs were involved. In the absence of direct instruction, young children show sensitivity to the degree of differentiation afforded by feature-function relations.     

Brief motivational intervention with homeless adolescents: evaluating effects on substance use and service utilization.

A brief motivational intervention with 117 homeless adolescents was evaluated using a randomized design and 3-month follow-up. The intervention was designed to raise youths' concerns about their substance use, support harm reduction, and encourage greater service utilization at a collaborating agency. The study was designed to strengthen initial promising results of an earlier study (P. L. Peterson, J. S. Baer, E. A. Wells, J. A. Ginzler, & S. B. Garrett, 2006). Several modifications in the clinical protocol were included to enhance engagement with the intervention. Analyses revealed no significant benefits for intervention participants when homeless youths' substance use rates were compared with those of control participants. Service utilization during the intervention period increased for those receiving the intervention but returned to baseline levels at follow-up. Participants reported overall reductions in substance use over time. Differences between sampling methods for the current and previous study are discussed, as are the limitations of brief interventions with this population. Future research needs to elucidate mechanisms of change and service engagement for highly vulnerable youth.     

Aggression, psychopathy and free will from a cognitive neuroscience perspective

This article considers the notion of free will in the context of aggression and psychopathy research. The philosophical literature is very briefly considered to determine under what assumptions free will can be considered to exist. However, as the issue of free will is very difficult to address directly, the prime focus of this article is on issues raised in the philosophical debate, that may be empirically tractable and that are relevant to the understanding of psychopathy. Specifically, the following issues are considered: (1) The distinction between automatic and controlled processing; (2) Impairment related to automatic processing in individuals with psychopathy; and (3) Impairment related to controlled behavior in individuals with psychopathy. It is concluded that, while there is not a direct mapping of the automatic versus controlled processing dichotomy on to the reactive versus instrumental aggression dichotomy, some overlap can be considered. As such, it is possible to consider that certain episodes of reactive aggression might be considered to occur in the absence of free will. However, instrumental aggression, at least from a compatibilist perspective, must involve free will.     

The development of executive function in early childhood is inversely related to change in body mass index: Evidence for an energetic tradeoff?

A well‐established literature demonstrates executive function (EF) deficits in obese children and adults relative to healthy weight comparisons. EF deficits in obesity are associated with overeating and impulsive consumption of high calorie foods leading to excess weight gain and to problems with metabolic regulation and low‐grade inflammation that detrimentally affect the structure and function of prefrontal cortex. Here, we test a complementary explanation for the relation between EF and body mass index (BMI) grounded in the energy demand of the developing brain. Recent work shows that the brain accounts for a lifetime peak of 66% of resting metabolic rate in childhood and that developmental changes in brain energetics and normative changes in body weight gain are closely inversely related. This finding suggests a trade‐off in early childhood between energy used to support brain development versus energy used to support physical growth and fat deposition. To test this theorized energetic trade‐off, we analyzed data from a large longitudinal sample (N = 1,292) and found that change in EF from age 3 to 5 years, as a proxy for brain development in energetically costly prefrontal cortex, is inversely related to change in BMI from age 2 to 5 years. Greater linear decline in BMI predicted greater linear increase in EF. We interpret this finding as tentative support for a brain–body energetic trade‐off in early childhood with implications for lifetime obesity risk.     

Expertise in Deception Detection Involves Actively Prompting Diagnostic Information Rather Than Passive Behavioral Observation

In a proof‐of‐concept study, an expert obtained 100% deception‐detection accuracy over 33 interviews. Tapes of the interactions were shown to N = 136 students who obtained 79.1% accuracy (Mdn = 83.3%, mode = 100%). The findings were replicated in a second experiment with 5 different experts who collectively conducted 89 interviews. The new experts were 97.8% accurate in cheating detection and 95.5% accurate at detecting who cheated. A sample of N = 34 students watched a random sample of 36 expert interviews and obtained 93.6% accuracy. The data suggest that experts can accurately distinguish truths from lies when they are allowed to actively question a potential liar, and nonexperts can obtain high accuracy when viewing expertly questioned senders.