Sex, mathematics, and the brain: An evolutionary perspective

Gender Differences in the Wechsler Intelligence Scale for Children in a Large Group of Italian Children with Attention Deficit Hyperactivity Disorder

Despite being repeatedly investigated in children with typical development, research on gender differences in intellectual abilities in specific groups of children, including children with attention deficit hyperactivity disorder (ADHD), has been scarce. In this paper, we evaluated the performance of a large group of Italian children with ADHD using the WISC-IV. We aimed at investigating the presence of gender differences using a multi-group confirmatory factor analysis approach. Results showed that the WISC is largely gender-invariant. However, some tasks present non-invariant patterns (block design and coding). Differences at the latent level also showed some differences (favoring boys) in the verbal comprehension index. Conversely, differences at the latent level were not found in the full-scale IQ or in the other main indices. These results have theoretical and practical implications.

Numeracy, gist, literal thinking and the value of nothing in decision making

The onus on the average person is greater than ever before to make sense of large amounts of readily accessible quantitative information, but the ability and confidence to do so are frequently lacking. Many people lack practical mathematical skills that are essential for evaluating risks, probabilities and numerical outcomes such as survival rates for medical treatments, income from retirement savings plans or monetary damages in civil trials. In this Review, we integrate research on objective and subjective numeracy, focusing on cognitive and metacognitive factors that distort human perceptions and foment systematic biases in judgement and decision making. Paradoxically, an important implication of this research is that a literal focus on objective numbers and mechanical number crunching is misguided. Numbers can be a matter of life and death but a person who uses rote strategies (verbatim representations) cannot take advantage of the information contained in the numbers because 'rote' strategies are, by definition, processing without meaning. Verbatim representations (verbatim is only surface form, not meaning) treat numbers as data as opposed to information. We highlight a contrasting approach of gist extraction: organizing numbers meaningfully, interpreting them qualitatively and making meaningful inferences about them. Efforts to improve numerical cognition and its practical applications can benefit from emphasizing the qualitative meaning of numbers in context - the gist - building on the strengths of humans as intuitive mathematicians. Thus, we conclude by reviewing evidence that gist training facilitates transfer to new contexts and, because it is more durable, longer-lasting improvements in decision making.

Evolution of Self-Awareness and the Cultural Emergence of Academic and Non-academic Self-Concepts

Schooling is ubiquitous in the modern world and academic development is now a critical aspect of preparation for adulthood. A step back in time to pre-modern societies and an examination of life in remaining traditional societies today reveals that universal formal schooling is an historically recent phenomenon. This evolutionary and historical recency has profound implications for understanding academic development, including how instructional practices modify evolved or biological primary abilities (e.g., spoken language) to create evolutionarily novel or biologically secondary academic competencies (e.g., reading). We propose the development of secondary abilities promotes the emergence of academic self-concepts that in turn are supported by evolved systems for self-awareness and self-knowledge. Unlike some forms of self-knowledge (e.g., relative physical abilities) that appear to be universal and central to many people's overall self-concept, the relative importance of academic self-concepts are expected to be dependent on explicit social and cultural supports for their valuation. These culturally contingent self-concepts are contrasted with universal social and physical self-concepts, with implications for understanding variation students' relative valuation of academic competencies and their motivations to engage in academic learning.