Meta-analysis supports cognitive ability differentiation hypotheses (SLODOR)

A B S T R A C T

The cognitive ability differentiation hypothesis, which is also termed Spearman's Law of Diminishing Returns, proposes that cognitive ability tests are less correlated and less g loaded in higher ability populations. In ad-dition, the age differentiation hypothesis proposes that the structure of cognitive ability varies across respondent age. To clarify the literature regarding these expectations, 106 articles containing 408 studies, which were published over a 100-year time span, were analyzed to evaluate the empirical basis for ability as well as age differentiation hypotheses. Meta-analyses provide support for both hypotheses and related expectations. Results demonstrate that the mean correlation and g loadings of cognitive ability tests decrease with increasing ability, yet increase with respondent age. Moreover, these effects have been nearly constant throughout the century of analyzed data. These results are important because we cannot assume an invariant cognitive structure for dif-ferent ability and age levels. Implications for practice as well as drawbacks are further discussed.

Federal Court Rules to Protect the Interest of Incompetent North Carolina Death-Row Exoneree

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Federal Court Rules to Protect the Interest of Incompetent North Carolina Death-Row Exoneree
// Death Penalty Information Center

A federal judge has voided a contract that had provided Orlando-based attorney Patrick Megaro hundreds of thousands of dollars of compensation at the expense of Henry McCollum (pictured left, with his brother Leon Brown), an intellectually disabled former death-row prisoner who was exonerated in 2014 after DNA testing by the North Carolina Innocence Inquiry Commission showed that he had not committed the brutal rape and murder of a young girl for which he had been wrongly convicted and condemned. McCollum and Brown—who both have IQs measured in the 50s and 60s—had been convicted in 1983 based on coerced false confessions that the brothers (aged 19 and 15 at the time) provided to interrogating officers. At the time of his exoneration, McCollum had spent 30 years on death row and was the state's longest serving death-row prisoner. Megaro became McCollum's and Brown's lawyer in March 2015, after two women who claimed to be advocating on behalf of the brothers persuaded them to fire the lawyers who had been representing them in their efforts to obtain compensation and to hire Megaro's firm. McCollum was awarded $750,000 in compensation from North Carolina in October 2015, at least half of which appears to have been paid to Megaro. Within seven months, McCollum was out of money and taking out high-interest loans that had been arranged and approved by Megaro. Megaro also negotiated a proposed settlement of the brothers' wrongful prosecution lawsuit in which he was to receive $400,000 of a $1 million payment to the brothers. Defense lawyer Ken Rose, who represented McCollum for 20 years and helped win McCollum's release from prison, provided testimony that two mental experts had previously found that McCollum was "not competent to provide a confession" and that McCollum remained "vulnerable to manipulation and control by others." After hearing additional evidence from experts and other witnesses, U.S. District Court Judge Terrence Boyle determined that, as a result of his intellectual disability, McCollum lacked knowledge and understanding of financial issues, "remains easily manipulated," and was "unable to make important decisions about his person and property." As a result, the court voided the contract between McCollum and Megano, including the fee arrangements. Raymond Tarlton, whom Judge Boyle appointed to serve as McCollum's guardian ad litem, said the decision "made clear that the same disabilities that led to Henry McCollum giving a false confession in 1983 made him vulnerable to be manipulated and controlled after release." The court also has appointed a guardian to protect the interests of Leon Brown. Judge Boyle ordered further briefing pending receipt of the guardian's report to assist in determining the status of the contract between Megaro and Brown.
(Judge nixes high attorney fees for NC man wrongly sentenced to death, Associated Press, October 24, 2017; J. Neff, Innocent, Disabled and Vulnerable, The Marshall Project, October 24, 2017; Editorial: Judge finally rules to benefit of half-brothers, The Robesonian, October 24, 2017.) Read the court's order. See Innocence and Intellectual Disability.

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CFA of WISC-V: A five factor CHC battery

There are dueling factor study articles regarding the WISC-V in the research literature. Here is the take of Reynolds and Keith, who, IMHO, tend to do some of the best factor structure research in intelligence testing.

The five factors look like clear Gc, Gv, Gf, Gwm and Gs CHC factors.

Abstract

The purpose of this research was to test the consistency in measurement of Wechsler Intelligence Scale for Chil-dren-Fifth Edition (WISC-V; Wechsler, 2014) constructs across the 6 through 16 age span and to understand the constructs measured by the WISC-V. First-order, higher-order, and bifactor confirmatory factor models were used. Results were compared with two recent studies using higher-order and bifactor exploratory factor analysis (Canivez, Watkins, & Dombrowski, 2015; Dombrowski, Canivez, Watkins, & Beaujean, 2015) and two using con-firmatory factor analysis (Canivez, Watkins, & Dombrowski, 2016; Chen, Zhang, Raiford, Zhu, & Weiss, 2015). We found evidence of age-invariance for the constructs measured by the WISC-V. Further, both g and five distinct broad abilities (Verbal Comprehension, Visual Spatial Ability, Fluid Reasoning, Working Memory, and Processing Speed) were needed to explain the covariances among WISC-V subtests, although Fluid Reasoning was nearly equivalent to g. These findings were consistent whether a higher-order or a bifactor hierarchical model was used, but they were somewhat inconsistent with factor analyses from the prior studies. We found a correlation between Fluid Reasoning and Visual Spatial factors beyond a general factor (g) and that Arithmetic was primarily a direct indicator of g. Composite scores from the WISC-V correlated well with their corresponding underlying factors. For those concerned about the fewer numbers of subtests in the Full Scale IQ, the model implied relation between g and the FSIQ was very strong.

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SCOTUS orders Florida to reconsider Atkins case in light of Moore v Texas: Tavares Wright

The United States Supreme Court has ordered the Florida Supreme Court to reconsider a decision that had denied a death-row prisoner's claim that he was ineligible for the death penalty because he has Intellectual Disability. On October 16, the Court reversed and remanded the case of Tavares Wright (pictured, left), directing the Florida courts to reconsider his intellectual-disability claim in light of the constitutional standard the Court set forth in its March 2017 decision in Moore v. Texas.

More information can be found here.

"Neuroscience Nuance: Dissecting the Relevance of Neuroscience in Adjudicating Criminal Culpability"

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"Neuroscience Nuance: Dissecting the Relevance of Neuroscience in Adjudicating Criminal Culpability"
// Sentencing Law and Policy

The title of this post is the title of this notable new paper authored by Christopher Slobogin. Even more than the title, the paper's abstract suggests it is a must-read for sentencing fans:

Most scholars who have written about the role of neuroscience in determining criminal liability and punishment take a stance somewhere between those who assert that neuroscience has virtually nothing to say about such determinations and those that claim it will upend the assumption that most choices to commit crime are blameworthy.  At the same time, those who take this intermediate position have seldom clarified how they think neuroscience can help. This article tries to answer that question more precisely than most works in this vein.  It identifies five types of neuroscience evidence that might be presented by the defense and discusses when that evidence is material under accepted legal doctrine.  It concludes that, even on the assumption that the data presented are accurate, much commonly proffered neuroscientific evidence is immaterial or only weakly material, not only at trial but also at sentencing. At the same time, it recognizes that certain types of neuroscience evidence can be very useful in criminal adjudication, especially at sentencing.

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Law Review Article: Lucas (2017) An Empirical Assessment of Georgia's Beyond a Reasonable Doubt Standard to Determine Intellectual Disability in Capital Cases

This article can be found at this link.


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Atkins-related Court decision: Cathey v Davis (2017, Texas)

For some reason I failed to post the most recent court decision this past May regarding Cathey, a case where the Flynn effect (norm obsolescence) is prominent. This decision can now be found here. The court granted Cathey a district court hearing to present evidence regarding the Flynn effect in his Atkins claim. Prior Cathey related posts can be found here.


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