Psychometric Intelligence Research Articles

Elucidating the functional relationship between working memory capacity and psychometric intelligence: a fixed-links modeling approach for experimental repeated-measures designs.

Numerous studies reported a strong link between working memory capacity (WMC) and fluid intelligence (Gf), although views differ in respect to how close these two constructs are related to each other. In the present study, we used a WMC task with five levels of task demands to assess the relationship between WMC and Gf by means of a new methodological approach referred to as fixed-links modeling. Fixed-links models belong to the family of confirmatory factor analysis (CFA) and are of particular interest for experimental, repeated-measures designs. With this technique, processes systematically varying across task conditions can be disentangled from processes unaffected by the experimental manipulation. Proceeding from the assumption that experimental manipulation in a WMC task leads to increasing demands on WMC, the processes systematically varying across task conditions can be assumed to be WMC-specific. Processes not varying across task conditions, on the other hand, are probably independent of WMC. Fixed-links models allow for representing these two kinds of processes by two independent latent variables. In contrast to traditional CFA where a common latent variable is derived from the different task conditions, fixed-links models facilitate a more precise or purified representation of the WMC-related processes of interest. By using fixed-links modeling to analyze data of 200 participants, we identified a non-experimental latent variable, representing processes that remained constant irrespective of the WMC task conditions, and an experimental latent variable which reflected processes that varied as a function of experimental manipulation. This latter variable represents the increasing demands on WMC and, hence, was considered a purified measure of WMC controlled for the constant processes. Fixed-links modeling showed that both the purified measure of WMC (β = .48) as well as the constant processes involved in the task (β = .45) were related to Gf. Taken together, these two latent variables explained the same portion of variance of Gf as a single latent variable obtained by traditional CFA (β = .65) indicating that traditional CFA causes an overestimation of the effective relationship between WMC and Gf. Thus, fixed-links modeling provides a feasible method for a more valid investigation of the functional relationship between specific constructs.

The relationship of choice reaction time variability and intelligence: A meta-analysis

Frequently the relationship of the variability of reaction times (RTSD) on elementary cognitive tasks and psychometric general intelligence (g) has been investigated. A typical finding is that stable reaction times (low RTSDs) on very basic choice reaction tasks are associated with high g. This meta-analysis quantifies the phenomenon by integrating 24 studies of 27 independent samples with a total of 3968 subjects using comparable, Hick-derived paradigms (Hick 0, 1, 2, 3bit; odd-man-out). Special attention was given to the disattenuation of correlations for reliability artefacts. Random effect meta-analysis yielded small to moderate relationships between intelligence and reaction time variability, the pooled Pearson correlation ranging between −.18 (0bit) and −.28 (2bit). The relationship did not, however, prove consistently larger than the one between intelligence and reaction time, in contrast to earlier findings.

Do We Have Valid Country-Level Measures of Personality?

While country-level differences in psychometric intelligence and school achievement are used increasingly in cross-cultural research, far less is known about country-level differences in personality. This article summarizes cross-country research with measures of the Big Five personality dimensions. The conclusion is that these measures have limited reliability and validity when used at the level of country averages. Possible reasons and remedies for this situation are discussed.

Academic achievement: Intelligence, regulatory, and cognitive predictors

IntroductionThe psychological factors in academic success are a hot point in modern psychology. For a long time research efforts have been focused on cognitive features and intelligence as predictors of academic success. Yet empirical results differ in assessing the contribution of intelligence to academic achievement. According to meta-analysis results, some researchers report that the interrelationship between academic success and psychometric intelligence is determined within 0.29-0.40 (Gordeeva, 2013; Kornilov, Grigorenko, & Smirnov, 2009), while other studies reveal this interrelationship to be 0.40-0.63 (Bartels, Rietveld, Van Baal, & Boomsma, 2002; Brody, 2004; Krapohl et al., 2014; Spinath, Spinath, Harlaar, & Plomin, 2006; Sternberg, Grigorenko, & Bundy, 2001). However, researchers point out that intelligence is a key predictor of students' academic success; intelligence explains 25% of the variance of indicators of academic success (Gottfredson, 2004; Sternberg et al., 2001).Many research efforts are focused on the noncognitive factors influencing students' academic success. Scientists discovered among them a number of personal predictors: motivation, self-esteem, self-efficacy, personal potential, and the Big Five factors (Gordeeva, Leontiev, & Osin, 2011; Gordeeva & Osin, 2012; Kochergina, Nye, & Orel, 2013; Kornilova, Kornilov, & Chumakova, 2009; Kornilova & Novikova, 2013; Krapohl et al., 2014; Smirnov, Kornilova, Kornilov, & Malakhova, 2007; Spinath et al, 2006; Steinmayr & Spinath, 2009).In addition, researchers have suggested self-regulation (SR) as an essential factor in students' academic success (Boekaerts, Pintrich, & Zeidner, 2005; Diseth & Kobbeltvedt, 2010; Elliot, McGregor, & Gable, 1999; Pintrich & De Groot, 1990; Zimmerman & Schunk, 1989). However, there is no common understanding of what a phenomenon of SR is and which features are to be considered SR components. Most researchers focus on goal setting -- the ability to set learning goals (Schunk, 1990; Zimmerman, Bandura, & Martinez-Pons, 1992). Other scientists analyze volitional (Corno, 2001), cognitive (Winne, 1995), and sociocultural (McCaslin and Hickey, 2001) aspects of SR.In Russia the problem of the interrelationship between SR and academic achievement is considered in the context of both personality psychology (Ivannikov, 2006; Leontiev, 2011) and cognitive psychology (Kornilova, 2008; Sergienko, 2008). It is difficult to interpret conscious SR as a purely personal or cognitive factor. Nowadays SR is often viewed as a meta-cognitive process that organizes learning by coordinating primary cognitive processes (Karpov, 2011). Overall, it is a paradoxical situation: the impact of SR on learning activity is not disputed, but the contribution of regulatory processes is difficult to assess because of different methodological positions resulting in different research organization.The main goal of the present article is to introduce the standpoint of the scientific school of SR psychology developed by the Psychological Institute of the Russian Academy of Education. Equally important to us is the task of evaluating and comparing the contribution of regulatory, cognitive, and intellectual factors to academic success based on the results of our recent empirical studies.The basic concept: Self-regulationWe define self-regulation as a process of conscious self-organization of psychic activity that assures goal setting and achievement of results corresponding to these goals. SR is realized through a wholesome, multilevel system that has a particularstructure of interrelated components. A conceptual model of the conscious SR system includes the main functional components: activity goal (as it is understood and accepted by the subject); subjective model of the activity conditions significant for goal achievement; program of the activity; system of criteria for goal achievement; evaluation and correction of the activity results (Konopkin, 2011). …

Attentional Control and Intelligence: MRI Orbital Frontal Gray Matter and Neuropsychological Correlates.

Attentional control is a key function of working memory that is hypothesized to play an important role in psychometric intelligence. To test the neuropsychological underpinnings of this hypothesis, we examined full-scale IQ, as measured by the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III), and attentional control, as measured by Trails B response time and Wisconsin Card Sorting (WCS) test perseverative errors in 78 healthy participants, 25 of whom also had available magnetic resonance imaging (MRI) gray matter volume studies of the orbital frontal cortex (OFC) parcellated into three regions: gyrus rectus, middle orbital gyrus, and lateral orbital gyrus. Hierarchical regression indicated that Trails B response time specifically explained 15.13% to 19.18% of the variation in IQ and WCS perseverative errors accounted for an additional 8.12% to 11.29% of the variance. Full-scale IQ correlated very strongly with right middle orbital gyrus gray matter volume (r = 0.610, p = 0.002), as did Trails B response time with left middle orbital gyrus gray matter volume (r = −0.608, p = 0.003). Trails B response time and right middle orbital gyrus gray matter volume jointly accounted for approximately 32.95% to 54.82% of the variance in IQ scores. These results provided evidence of the unique contributions of attentional control and OFC gray matter to intelligence.

A retenção fatorial na abordagem intraindividual: proposição de uma estratégia de triangulação

The intra-individual approach has been proposed by researchers as an alternative to traditional techniques focused on the population level. The central argument is that the inter-individual procedures are appropriate to estimate the population variance but cannot be extrapolated to the individual level. Evidence shows that the factorial structure of intelligence and personality psychometric models usually verified in the population (e.g. Carrol’s three strata factor structure and the Big Five Personality model) are not necessarily found at the individual level. However, the factor analysis in the intra-individual approach has an additional challenge in comparison to the traditional factor analysis: until the present moment there are no fit indices available to the intra-individual factor techniques. The current paper proposes the use of a set of approaches to find the adequate factor retention as a triangulation of data. The proposition will be applied in the psychometric intelligence field

Parents' SES vs. parental educational behavior and children's development: A reanalysis of the Hart and Risley study

In their seminal study “Meaningful differences in the everyday experience of young American children”, Hart and Risley (1995) showed a close relationship between differences in family environment and children's development. The conventional conclusion was that children's cognitive development (measured by psychometric intelligence and verbal ability tests) depends on parental socioeconomic status (SES), especially on wealth. We reanalyzed their data and show that the quality of education given by parents is crucial (βPEB=.58) and not the diffuse aggregate measure of SES (βSES=.11). Additionally, we compare their sample with a similar but larger sample (Hoff, 2003) showing the same pattern of results. Possible causal factors (associated environmental and genetic factors) are discussed.

Lower Verbal Ability in Japanese Delinquents Using the Wechsler Intelligence Scale for Children Fourth Edition: A Preliminary Investigation

The relationship between juvenile delinquency and psychometric intelligence is supported by studies in behavioral sciences. In this literature, lower verbal ability is reported as an intellectual characteristic that is common in juvenile delinquents, based on assessment using the Wechsler scales. These scales incorporate the dual intelligence model, which includes both a Verbal Intelligence Quotient (VIQ) and a Performance IQ (PIQ). A meta-analysis conducted by Isen (2010) analyzed 131 studies to examine the discrepancy between PIQ and VIQ on the Wechsler Intelligence Scale for Children (WISC), WISC-R, and WISC-III among antisocial adolescents and children. The results revealed that the PIQ score of antisocial individuals was six points higher than their VIQ score in adolescents, and did not differ significantly from their VIQ score in young children. The lowest subtests were Vocabulary and Information on the WISC for delinquent adolescents. The most current version of the Wechsler series test (i.e., WISC-IV) was excluded from the meta-analysis because the WISC-IVadopted the four factors model instead of the traditional dual intelligence model. A few researchers have studied the intelligence of populations with criminal histories using the WISC-IV (e.g., Lopez-Leon and Rosner 2010; Sinclair et al. 2013). Lopez-Leon and Rosner (2010) examined the evaluation of clinical history in 27 adolescent defendants after committing violent crimes. Their cognitive abilities were assessed using the WISC-IV. The Full-Scale IQ (FSIQ) and four composite scores of the defendants were compared with the norm of the standardization sample (M=100, SD=15). Results showed that violent juveniles had lower scores on the FSIQ (M=82.9), a score of 78.5 on the Processing Speed Index (PSI), a Perceptual Reasoning Index (PRI) score of 87.8, and a Verbal Comprehension Index (VCI) score of 86.7. However, there was no difference when comparing the defendants to the standardized sample on the Working Memory Index (WMI; M=90.8). Perhaps, these results were due to the low statistical power of only 27 participants. In another study, Sinclair et al. (2013) investigated the relationship among neuropsychological deficits, antisocial behavior, and intelligence using the WISC-IV. Participants were 28 adolescents and children between 9 Asian Criminology (2014) 9:323–328 DOI 10.1007/s11417-014-9195-5

General intelligence predicts memory change across sleep.

Psychometric intelligence (g) is often conceptualized as the capability for online information processing but it is also possible that intelligence may be related to offline processing of information. Here, we investigated the relationship between psychometric g and sleep-dependent memory consolidation. Participants studied paired-associates and were tested after a 12-hour retention interval that consisted entirely of wake or included a regular sleep phase. We calculated the number of word-pairs that were gained and lost across the retention interval. In a separate session, participants completed a battery of cognitive ability tests to assess g. In the wake group, g was not correlated with either memory gain or memory loss. In the sleep group, we found that g correlated positively with memory gain and negatively with memory loss. Participants with a higher level of general intelligence showed more memory gain and less memory loss across sleep. Importantly, the correlation between g and memory loss was significantly stronger in the sleep condition than in the wake condition, suggesting that the relationship between g and memory loss across time is specific to time intervals that include sleep. The present research suggests that g not only reflects the capability for online cognitive processing, but also reflects capability for offline processes that operate during sleep.

Lesion mapping of social problem solving.

Accumulating neuroscience evidence indicates that human intelligence is supported by a distributed network of frontal and parietal regions that enable complex, goal-directed behaviour. However, the contributions of this network to social aspects of intellectual function remain to be well characterized. Here, we report a human lesion study (n = 144) that investigates the neural bases of social problem solving (measured by the Everyday Problem Solving Inventory) and examine the degree to which individual differences in performance are predicted by a broad spectrum of psychological variables, including psychometric intelligence (measured by the Wechsler Adult Intelligence Scale), emotional intelligence (measured by the Mayer, Salovey, Caruso Emotional Intelligence Test), and personality traits (measured by the Neuroticism-Extraversion-Openness Personality Inventory). Scores for each variable were obtained, followed by voxel-based lesion-symptom mapping. Stepwise regression analyses revealed that working memory, processing speed, and emotional intelligence predict individual differences in everyday problem solving. A targeted analysis of specific everyday problem solving domains (involving friends, home management, consumerism, work, information management, and family) revealed psychological variables that selectively contribute to each. Lesion mapping results indicated that social problem solving, psychometric intelligence, and emotional intelligence are supported by a shared network of frontal, temporal, and parietal regions, including white matter association tracts that bind these areas into a coordinated system. The results support an integrative framework for understanding social intelligence and make specific recommendations for the application of the Everyday Problem Solving Inventory to the study of social problem solving in health and disease.

No evidence for true training and transfer effects after inhibitory control training in young healthy adults.

Recent studies reported that training of working memory may improve performance in the trained function and beyond. Other executive functions, however, have been rarely or not yet systematically examined. The aim of this study was to test the effectiveness of inhibitory control (IC) training to produce true training-related function improvements in a sample of 122 healthy adults using a randomized, double-blind pretest/posttest/follow-up design. Two groups performed either adaptive (training group) or nonadaptive (active control) versions of go/no-go and stop-signal tasks for 3 weeks. Training gains as well as near-transfer to an untrained Stroop task and far-transfer to psychometric fluid intelligence were explored. Although the adaptive group could substantially improve overall IC task performance after training, no differences to the active control group occurred, neither at posttest nor at follow-up testing. A large decrease in response latency from pre- to posttest (and from pretest to 4 months' follow-up testing) was found when the training group was compared to the passive control group, which, however, does not sufficiently control for possible confounds. Thus, no conclusive evidence was found that this performance increase mirrors a true increase in IC function. The fact that training improvement was mainly related to response latency may indicate that individuals were more focused on performance gains in the prepotent go trials but less on the stop trials to meet the requirements of the tasks as well as possible. The challenges for response inhibition training studies are extensively discussed.

Genetic and environmental stability of intelligence in childhood and adolescence.

The present study examined the genetic and environmental contributions to the temporal stability of verbal, non-verbal and general intelligence across a developmental period spanning childhood and adolescence (5-18 years). Longitudinal twin data collected in four different studies on a total of 1,748 twins, comprising 4,641 measurement points in total, were analyzed using genetic adaptations of the simplex model. The heterogeneity in the type of instrument used to assess psychometric intelligence across the different subsamples and ages allowed us to address the auxiliary question of how to optimally utilize the existing longitudinal data in the context of gene-finding studies. The results were consistent across domains (verbal, non-verbal and general intelligence), and indicated that phenotypic stability was driven primarily by the high stability of additive genetic factors, that the stability of common environment was moderate, and that the unique environment contributed primarily to change. The cross-subscale stability was consistently low, indicating a small overlap between different domains of intelligence over time. The high stability of additive genetic factors justifies the use of a linear combination of scores across the different ages in the context of gene-finding studies.

Individual differences in working memory capacity explain the relationship between general discrimination ability and psychometric intelligence

The close association between psychometric intelligence and general discrimination ability (GDA), conceptualized as latent variable derived from performance on different sensory discrimination tasks, is empirically well-established but theoretically widely unclear. The present study contrasted two alternative explanations for this association. The first explanation is based on what Spearman (1904) referred to as a central function underlying this relationship in the sense of the g factor of intelligence and becoming most evident in GDA. In this case, correlations between different aspects of cognitive abilities, such as working memory (WM) capacity, and psychometric intelligence should be mediated by GDA if their correlation is caused by g. Alternatively, the second explanation for the relationship between psychometric intelligence and GDA proceeds from fMRI studies which emphasize the role of WM functioning for sensory discrimination. Given the well-known relationship between WM and psychometric intelligence, the relationship between GDA and psychometric intelligence might be attributed to WM. The present study investigated these two alternative explanations at the level of latent variables. In 197 young adults, a model in which WM mediated the relationship between GDA and psychometric intelligence described the data better than a model in which GDA mediated the relationship between WM and psychometric intelligence. Moreover, GDA failed to explain portions of variance of psychometric intelligence above and beyond WM. These findings clearly support the view that the association between psychometric intelligence and GDA must be understood in terms of WM functioning.

La teoría de las inteligencias múltiples en la identificación de alum-nos de altas habilidades (superdotación y talento).

This study provides a framework to implement the theory of multiple intelligences (MI) in the identification of high-ability students in secondary education. The internal structure of three scales to assess students’ MI (students, parents and teachers’ ratings) was analyzed in a sample of 566 students nominated as gifted by their teachers. Participants aged 11 to 16 years (M = 14.85, SD = 1.08). The results indicated differentiated intellectual profiles depending on the informant estimating students’ MI. This study provided evidence for two components that allow us to analyze the cognitive competence of high-ability students beyond the areas commonly assessed at school: an academic component composed by the linguistic, logical-mathematical, naturalistic, and visual-spatial intelligences; and a non-academic component statistically loaded by the bodily-kinesthetic, musical and social intelligences. Convergence of the two components in the three scales was evidenced; and correlations between these components and students’ objective performance on a psychometric intelligence test were found to be low. Finally, the utility of the MI scales to identify high-ability students in secondary education is discussed.

Moderate relationships between NAA and cognitive ability in healthy adults: implications for cognitive spectroscopy

Background: Proton Magnetic Resonance Spectroscopy (1H-MRS) is a non-invasive imaging technique that enables quantification of neurochemistry in vivo and thereby facilitates investigation of the biochemical underpinnings of human cognitive variability. Studies in the field of cognitive spectroscopy have commonly focused on relationships between measures of N-acetyl aspartate (NAA), a surrogate marker of neuronal health and function, and broad measures of cognitive performance, such as IQ.Methodology/Principal Findings: In this study, we used 1H-MRS to interrogate single-voxels in occipitoparietal and frontal cortex, in parallel with assessments of psychometric intelligence, in a sample of 40 healthy adult participants. We found correlations between NAA and IQ that were within the range reported in previous studies. However, the magnitude of these effects was significantly modulated by the stringency of data screening and the extent to which outlying values contributed to statistical analyses.Conclusions/Significance: 1H-MRS offers a sensitive tool for assessing neurochemistry non-invasively, yet the relationships between brain metabolites and broad aspects of human behavior such as IQ are subtle. We highlight the need to develop an increasingly rigorous analytical and interpretive framework for collecting and reporting data obtained from cognitive spectroscopy studies of this kind.

Neural mechanisms of discourse comprehension: a human lesion study

Discourse comprehension is a hallmark of human social behaviour and refers to the act of interpreting a written or spoken message by constructing mental representations that integrate incoming language with prior knowledge and experience. Here, we report a human lesion study (n = 145) that investigates the neural mechanisms underlying discourse comprehension (measured by the Discourse Comprehension Test) and systematically examine its relation to a broad range of psychological factors, including psychometric intelligence (measured by the Wechsler Adult Intelligence Scale), emotional intelligence (measured by the Mayer, Salovey, Caruso Emotional Intelligence Test), and personality traits (measured by the Neuroticism-Extraversion-Openness Personality Inventory). Scores obtained from these factors were submitted to voxel-based lesion-symptom mapping to elucidate their neural substrates. Stepwise regression analyses revealed that working memory and extraversion reliably predict individual differences in discourse comprehension: higher working memory scores and lower extraversion levels predict better discourse comprehension performance. Lesion mapping results indicated that these convergent variables depend on a shared network of frontal and parietal regions, including white matter association tracts that bind these areas into a coordinated system. The observed findings motivate an integrative framework for understanding the neural foundations of discourse comprehension, suggesting that core elements of discourse processing emerge from a distributed network of brain regions that support specific competencies for executive and social function.

Relations between the attentional blink and aspects of psychometric intelligence: A fixed-links modeling approach

The attentional blink phenomenon (AB) represents impaired identification of the second of two targets presented in rapid succession within a stream of stimuli. Despite the well-known association between attentional processes and psychometric intelligence (PI), evidence for a relationship between AB and PI is highly inconsistent. Theory and empirical findings suggest AB to be multifaceted. Hence, relations between AB and PI may be blurred when AB is measured as a single process. Furthermore, different aspects of PI might be differentially related to AB. The present study explored the relationship between processes underlying AB and general PI as well as specific aspects of PI (Reasoning, Speed, Memory, and Creativity) in 201 female students. Fixed-links modeling revealed three processes underlying AB: (1) a U-shaped process positively related to Speed and negatively related to Memory but unrelated to Reasoning, Creativity, and general PI, (2) an increasing process positively related to Reasoning, Speed, Memory, and general PI but not to Creativity, and (3) a decreasing process positively related to general PI and Memory but not to other aspects of PI. Our findings demonstrate that dissociating processes underlying AB and considering specific aspects of PI is required to understand the relationship between AB and PI.

Vestibular evoked myogenic potentials (VEMPS) from upper limb muscles

Vestibular evoked myogenic potentials (VEMPS) from upper limb muscles

Developmental intelligence: From empirical to hidden constructs

This article answers some of the criticisms and suggestions of the three commentaries. We showed, in agreement with Coyle, that (i) variability is indeed distinct from speed, (ii) they both additively reflect processing efficiency and (iii) that they differentially relate to WM and gf during development. In agreement with Kail, we showed that developmental intelligence and psychometric intelligence are (i) related but distinct, they additively contribute to school learning and (iii) their role varies with developmental phase. Finally, in agreement with Pascual-Leone, we proposed a number of higher level hidden constructs to account for the data patterns observed between empirical constructs, such as speed, variability, WM, and reasoning.

Physically Developed and Exploratory Young Infants Contribute to Their Own Long-Term Academic Achievement

A developmental cascade defines a longitudinal relation in which one psychological characteristic uniquely affects another psychological characteristic later in time, separately from other intrapersonal and extrapersonal factors. Here, we report results of a large-scale (N = 374), normative, prospective, 14-year longitudinal, multivariate, multisource, controlled study of a developmental cascade from infant motor-exploratory competence at 5 months to adolescent academic achievement at 14 years, through conceptually related and age-appropriate measures of psychometric intelligence at 4 and 10 years and academic achievement at 10 years. This developmental cascade applied equally to girls and boys and was independent of children’s behavioral adjustment and social competence; mothers’ supportive caregiving, verbal intelligence, education, and parenting knowledge; and the material home environment. Infants who were more motorically mature and who explored more actively at 5 months of age achieved higher academic levels as 14-year-olds.