IQ & Intelligence Research
Peer-reviewed publications on cognitive ability, IQ measurement, and intelligence science.
Research Papers
Domain-Specific Knowledge as the "Dark Matter" of Adult Intelligence: Gf/Gc, Personality and Interest Correlates
An enduring controversy in intelligence theory and assessment, the argument that middle-aged adults are, on average, less intelligent than young adults, is addressed in this study. A sample of 228 ...
Molecular Genetic Contributions to Social Deprivation and Household Income in UK Biobank
Individuals with lower socio-economic status (SES) are at increased risk of physical and mental illnesses and tend to die at an earlier age [1-3]. Explanations for the association between SES and h...
Environment-Specific vs. General Knowledge and Their Role in Pro-environmental Behavior
Environmental knowledge has been established as a behavior-distal, but necessary antecedent of pro-environmental behavior. The magnitude of its effect is difficult to estimate due to methodological...
Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population
Cognitive impairment is common among individuals diagnosed with autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). It has been suggested that some aspects of intell...
Effects of general and broad cognitive abilities on mathematics achievement.
This study investigated the direct and indirect effects of general intelligence and 7 broad cognitive abilities on mathematics achievement. Structural equation modeling was used to investigate the ...
Working memory capacity, mind wandering, and creative cognition: An individual-differences investigation into the benefits of controlled versus spontaneous thought.
Should executive control, as indicated by working memory capacity (WMC) and mind-wandering propensity, help or hinder creativity? Sustained and focused attention should help guide a selective searc...
Influence of young adult cognitive ability and additional education on later-life cognition
How and when education improves cognitive capacity is an issue of profound societal importance. Education and later-life education-related factors, such as occupational complexity and engagement in...
A Theory of Adaptive Intelligence and Its Relation to General Intelligence
traditionally conceptualized in terms of a general factor in a psychometrically-based hierarchical model of intelligence, provides an optimal way of defining intelligence as adaptation to the envir...
Is education associated with improvements in general cognitive ability, or in specific skills?
Previous research has indicated that education influences cognitive development, but it is unclear what, precisely, is being improved. Here, we tested whether education is associated with cognitive...
The Contribution of Formal Schooling to the Increase in Intellectual Capital
Substantial IQ gains from one generation to the next have been recorded for men in many industrial societies since the 1950s. Some authors have attempted to argue away these results by claiming tha...
Genetic contributions to the association between height and intelligence: evidence from Dutch twin data from childhood to middle age
A positive association between intelligence (IQ) and height has been reported previously. It is generally assumed that this association reflects the effect of childhood environment on IQ, but there...
Secular changes in cognitive predictors of dementia and mortality in 70-year-olds
BACKGROUND: Successive elderly birth cohorts improved in cognitive performance during the 20th century. It is not clear whether this influences cognitive predictors of dementia and mortality. OBJEC...
Identifying Exceptional Talent in Science, Technology, Engineering, and Mathematics: Increasing Diversity and Assessing Creative Problem-Solving
In the Cultivating Diverse Talent in STEM project, funded by the National Science Foundation in the United States, new assessments were developed, field tested, used to identify students with excep...
Results of a “GWAS Plus:” General Cognitive Ability Is Substantially Heritable and Massively Polygenic
We carried out a genome-wide association study (GWAS) for general cognitive ability (GCA) plus three other analyses of GWAS data that aggregate the effects of multiple single-nucleotide polymorphis...
The Long-Term Cognitive and Socioeconomic Consequences of Birth Intervals: A Within-Family Sibling Comparison Using Swedish Register Data
We examine the relationship between birth-to-birth intervals and a variety of mid- and long-term cognitive and socioeconomic outcomes, including high school GPA, cognitive ability, educational atta...
Optimisation of thyroxine dose in congenital hypothyroidism
Optimum initial dosage remains unclear The introduction of the screening programme for congenital hypothyroidism in the late 1970s and early 1980s has been rightly hailed as a major success in the...
Neural Contributions to Reduced Fluid Intelligence across the Adult Lifespan
Fluid intelligence, the ability to solve novel, complex problems, declines steeply during healthy human aging. Using fMRI, fluid intelligence has been repeatedly associated with activation of a fro...
Parallelization: the Fourth Leg of Cultural Globalization Theory
Abstract Extending Pieterse’s (1996) tripartite cultural globalization theory consisting of homogenization, hybridization and polarization, the current article outlines a set of exemplifications ...
Birth cohort differences in cognitive performance in 75- and 80-year-olds: a comparison of two cohorts over 28 years
OBJECTIVE: To evaluate cohort differences in cognitive performance in older men and women born and assessed 28 years apart. METHODS: Data in this study were drawn from two age-homogeneous cohorts m...
Inequality/difference in New Zealand education: Social reproduction and the cognitive habitus
A programmatic study of inequality/difference in New Zealand education has been carried out, for a quarter of a century, within a family resource framework that has supported both theoretical and e...