Secular IQ increases by epigenesis? The hypothesis of cognitive genotype optimization

The short timescale of massive secular IQ gains ("Flynn Effect") is inconsistent with positive selection of a recent gene mutation, but other genetic mechanisms are possible. Principles of evolutionary psychology, combined with secular trends, suggest an epigenetic explanation: the Cognitive Genome Optimization Hypothesis. Per life-history theory, favorable secular trends may change the phenotypic expression of the genotype which controls the neurophysiology of problem solving. The hypothesis posits two intermediate steps between reliable nutrition (the starting point) and higher IQs (ending point): (1) Earlier cognitive maturation and (2) further calibration of cognitive function by reliable social resources (cultural complexity, mandatory education). Unlike earlier generations, more resources can be deployed to cognitive maturation than to physical survival, and more time is available to calibrate cognitive processing into the upper end of the trait value range for intelligence. The secular trend of earlier puberty timing is critical: data show an association between puberty and higher IQ.     

A misleading review of response bias: comment on McGrath, Mitchell, Kim, and Hough (2010)

In the May 2010 issue of Psychological Bulletin, R. E. McGrath, M. Mitchell, B. H. Kim, and L. Hough published an article entitled "Evidence for Response Bias as a Source of Error Variance in Applied Assessment" (pp. 450-470). They argued that response bias indicators used in a variety of settings typically have insufficient data to support such use in everyday clinical practice. Furthermore, they claimed that despite 100 years of research into the use of response bias indicators, "a sufficient justification for [their] use… in applied settings remains elusive" (p. 450). We disagree with McGrath et al.'s conclusions. In fact, we assert that the relevant and voluminous literature that has addressed the issues of response bias substantiates validity of these indicators. In addition, we believe that response bias measures should be used in clinical and research settings on a regular basis. Finally, the empirical evidence for the use of response bias measures is strongest in clinical neuropsychology. We argue that McGrath et al.'s erroneous perspective on response bias measures is a result of 3 errors in their research methodology: (a) inclusion criteria for relevant studies that are too narrow; (b) errors in interpreting results of the empirical research they did include; (c) evidence of a confirmatory bias in selectively citing the literature, as evidence of moderation appears to have been overlooked. Finally, their acknowledging experts in the field who might have highlighted these errors prior to publication may have prevented critiques during the review process.     

Actual versus self-reported scholastic achievement of litigating postconcussion and severe closed head injury claimants

Psychologists typically rely on patients' self-report of premorbid status in litigated settings. The authors examined the fidelity between self-reported and actual scholastic performance in litigating head injury claimants. The data indicated late postconcussion syndrome (LPCS) and severe closed head injury litigants retrospectively inflated scholastic performance to a greater degree than nonlitigating control groups. The LPCS group showed the highest magnitude of grade inflation, but discrepancy scores did not significantly correlate with a battery of malingering measures or with objective cerebral dysfunction. These findings support previous studies, which showed self-report is not a reliable basis for estimation of preinjury cognitive status. Retrospective inflation may represent a response shift bias shaped by an adversarial context rather than a form of malingering.