32 SD, ∼0.2 SD, and ∼0.3 SD, respectively) (Figure 4B), whereas the relationship with the verbal component was negligible. Conversely, while level of education (calculated from those aged 20+) showed a small-medium-sized positive relationship with the mean score (∼0.33) and the verbal score (0.32 SD), the STM score showed a smaller relationship selleck (0.23 SD), while the relationship with reasoning (0.12 SD)

was of negligible scale (Figure 4C). The STM and reasoning components were also dissociated from each other. For example, individuals who regularly suffer from anxiety (Figure 5A) had significantly lower mean scores (0.21 SDs), a relationship that was most pronounced for the STM component (0.35 SDs), with negligible reasoning (0.06 SDs) and verbal (−0.16 SDs) effect sizes. Similarly, while the differences between male and female participants’ mean (0.1 SD), verbal (0.03), and reasoning scores (−0.03) were negligible, males showed a small advantage over females on the STM component score (0.2 SD) (Figure 5B). Other significant factors included amount smoked (Figure 6A), with smokers performing worse than nonsmokers on the mean score (∼0.19 SD units), a difference that was most pronounced for the STM component (STM ≈ 0.19 SD, reasoning ≈ 0.09 SD, and verbal ≈ 0.05 SD). By contrast, alcohol GSK2656157 in vivo consumption and caffeine intake

showed negligible effect sizes for mean and component scores. Finally, geographical origin (grouped by country of birth) showed small-medium-sized relationships with Histamine H2 receptor a mean score (0.37 SD) that primarily favored individuals from countries in which English is the first language (Figure 6B). The largest relationship between component score and geographical origin was for the verbal component, which spanned ∼0.52 SD units, with smaller relationships evident for the reasoning (0.40 SD) and STM (0.23 SD) scores. (Note that rerunning the behavioral PCA and including only individuals

for whom English was the first language produced the same three-component solution.) Taken together, this combination of co-relationship and dissociation of the STM, reasoning, and verbal scores supports the view that these components have a basis in relatively independent systems, while demonstrating how a multifactor model can provide a more informative and balanced account of population differences in intelligence. Data from a pilot study were examined in order to confirm that the cognitive battery generated scores that correlated with “g” as measured by classic IQ testing. Thirty-five young healthy right-handed participants undertook the 12 cognitive tasks under controlled laboratory conditions followed by one of the most commonly applied classic pen and paper IQ tests—the Cattell Culture Fair (scale II).