A nationwide epidemiologic modeling study of LD: risk, protection, and unintended impact

Through multiple logistic regression modeling, this article explores the relative importance of risk and protective factors associated with learning disabilities (LD). A representative national sample of 6- to 17-year-old students (N = 1,268) was drawn by random stratification and classified by the presence versus absence of LD in reading, spelling, and mathematics according to ability-achievement discrepancies or low achievement levels. The dichotomous classifications were regressed on sets of explanatory variables indicating potential biological, social-environmental, and cognitive factors, problem behavior, and classroom learning behavior. Modeling revealed patterns of high risk for male students and students evincing verbal and nonverbal ability problems and processing speed problems. It was shown that, absent controls for cognitive abilities (such as provided by the ability-achievement discrepancy definition), definitions keyed to low achievement will substantially overidentify ethnic minority and disadvantaged students and will be confounded by significantly higher proportions of students who display oppositional and aggressive behavior problems. Alternatively, good learning behaviors uniformly provide substantial reduction in the risk for LD.

Was messen internationale Schulleistungsstudien?

Zusammenfassung. Über Aufgabenanalysen und die Analyse empirischer Beziehungen lässt sich bestimmen, was Tests wie die der internationalen Schulleistungsstudien (PISA, IGLU, TIMSS u.a.) messen. Inhaltliche Aufgabenanalysen belegen, dass Aufgaben unterschiedlicher Skalenzuordnung einander sehr ähnlich sind: Leseaufgaben enthalten Tabellen und Grafiken, Naturwissenschaftsaufgaben umfangreiche Lesetexte, Mathematikitems mit viel Text versehene alltagsnahe Denkaufgaben. Problemlösen ist konzeptuell am geringsten von Intelligenz zu unterscheiden. Zur Lösung der Aufgaben sind in unterschiedlichem Maße innerhalb der Bereiche Denken, Allgemeinwissen und Schulwissen notwendig. Empirische Beziehungen in Form von Korrelationen der Skalen untereinander, mit Intelligenztests und von Faktorenanalysen lassen sich in der Literatur nur schwierig oder gar nicht finden. Skaleninterkorrelationen bei Individualdaten liegen weit über den gängigen Skaleninterkorrelationen bei Intelligenztests. Skaleninterkorrelationen auf Ebene von Staaten sind extrem hoch; Korrelationen zwischen verschiedenen Studien und mit Intelligenztestergebnissen auf Ebene von Staaten sind hoch. Es finden sich selten Belege für diskriminante Validität. Alles spricht für die Messung eines g-Faktors kognitiver Fähigkeiten. Auf makrosozialer Ebene ist eine Unterscheidung von Intelligenz empirisch nicht möglich.

Leistungszuwachs in Mathematik

Zusammenfassung. Die vorliegende Arbeit geht der Frage nach, ob Schüler in der Mittelstufe in Abhängigkeit von der von ihnen besuchten Schulform unterschiedliche Lernzuwächse in der Mathematikleistung aufweisen. Die Existenz dieses auch als “Schereneffekt” bezeichneten Zusammenhangs wurde in einer neueren Arbeit von Schneider und Stefanek (2004) in Frage gestellt. Anhand einer Reanalyse der nationalen längsschnittlichen Erweiterung der deutschen TIMSS-Stichprobe (N = 1864 Schüler am Ende der 7. und Ende der 8. Klasse) wurde mit Hilfe von latent change-Modellen der Leistungszuwachs in Mathematik für Gymnasiasten, Real- und Hauptschüler in einem Mehrgruppen-Strukturgleichungsmodell untersucht. Es zeigten sich differenzielle Unterschiede im Leistungszuwachs zwischen allen drei Schulformen, die auf latenter Ebene zwischen .25 und .79 Standardabweichungen betrugen. Die Befunde sprechen für die Existenz des Schereneffekts in der Sekundarstufe.

Maternal education and intelligence predict offspring diet and nutritional status

The traditional assumption that children's nutritional deficiencies are essentially due either to overall food scarcity or to a lack of family resources to purchase available food has been increasingly questioned. Parental characteristics represent 1 type of noneconomic factor that may be related to variability in children's diets and nutritional status. We report evidence on the relation of 2 parental characteristics, maternal education level and maternal intelligence, to infant and toddler diet and nutritional status. Our sample consisted of 241 low-income Peruvian mothers and their infants assessed from 3 to 12 mo, with a further follow-up of 104 of these infants at 18 mo of age. Using a nonexperimental design, we related measures of level of maternal education, maternal intelligence, and family socioeconomic status to infant anthropometry, duration of exclusive breast-feeding, adequacy of dietary intake, and iron status. Results indicated unique positive relations between maternal education level and the extent of exclusive breast-feeding. Significant relations between maternal education and offspring length were partially mediated by maternal height. There also were unique positive relations between maternal intelligence and quality of offspring diet and hemoglobin level. All findings remained significant even after controlling for family socioeconomic characteristics. This pattern of results illustrates the importance of parental characteristics in structuring the adequacy of offspring diet. Maternal education and intelligence appear to have unique influences upon different aspects of the diet and nutritional status of offspring.

Modeling the effects of health status and the educational infrastructure on the cognitive development of Tanzanian schoolchildren

This paper models the proximate determinants of school attendance and scores on cognitive and educational achievement tests and on school examinations of over 600 schoolchildren from the Control group of a randomized trial in Tanzania, where children in the Intervention group heavily infected with hookworm and schistosomiasis received treatment. The modeling approach used a random effects framework and incorporated the inter-relationships between school attendance and performance on various tests, controlling for children's health status, socioeconomic variables, grade level, and the educational infrastructure. The empirical results showed the importance of variables such as children's height and hemoglobin concentration for the scores, especially on educational achievement tests that are easy to implement in developing countries. Also, teacher experience and work assignments were significant predictors of the scores on educational achievement tests, and there was some evidence of multiplicative effects of children's heights and work assignments on the test scores. Lastly, some comparisons were made for changes in test scores of treated children in the Intervention group with the untreated children in the Control group.

Kindergarten Predictors of Math Learning Disability

The aim of the present study was to address how to effectively predict mathematics learning disability (MLD). Specifically, we addressed whether cognitive data obtained during kindergarten can effectively predict which children will have MLD in third grade, whether an abbreviated test battery could be as effective as a standard psychoeducational assessment at predicting MLD, and whether the abbreviated battery corresponded to the literature on MLD characteristics. Participants were 226 children who enrolled in a 4-year prospective longitudinal study during kindergarten. We administered measures of mathematics achievement, formal and informal mathematics ability, visual-spatial reasoning, and rapid automatized naming and examined which test scores and test items from kindergarten best predicted MLD at grades 2 and 3. Statistical models using standardized scores from the entire test battery correctly classified ~80-83 percent of the participants as having, or not having, MLD. Regression models using scores from only individual test items were less predictive than models containing the standard scores, except for models using a specific subset of test items that dealt with reading numerals, number constancy, magnitude judgments of one-digit numbers, or mental addition of one-digit numbers. These models were as accurate in predicting MLD as was the model including the entire set of standard scores from the battery of tests examined. Our findings indicate that it is possible to effectively predict which kindergartners are at risk for MLD, and thus the findings have implications for early screening of MLD.

Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively.

Preschool competency in context: an investigation of the unique contribution of child competencies to early academic success

The present concurrent study combined developmental and ecological considerations to examine the unique contribution of multiple preschool competencies to an indicator of early academic success. Participants included 195 Head Start children from 32 classrooms representative of a large, urban Head Start program. Dimensional (variable-centered) analyses revealed 3 distinct classroom competency dimensions (i.e., General Classroom Competencies, Specific Approaches to Learning, and Interpersonal Classroom Behavioral Problems). The first 2 of these dimensions were found to be uniquely associated with early academic success. Findings from typological (person-centered) analyses supported the dimensional findings. Typological analyses revealed 7 profiles of classroom competency distinguished by high scores on the dimensions of General Competencies and Approaches to Learning, and these profiles were found to relate differentially to the indicator of early academic success.

Entwicklungsveränderungen allgemeiner kognitiver Fähigkeiten und schulbezogener Fertigkeiten im Kindes- und Jugendalter

Zusammenfassung. In einer Re-Analyse der Längsschnittdaten zur LOGIK-Studie ( Weinert & Schneider, 1999 ) wurde der Frage nachgegangen, ob sich differentielle Entwicklungsmuster im Sinne eines “Schereneffekts“ für unterschiedliche kognitive Merkmale bei intellektuell fähigeren und weniger fähigen Probanden nachweisen lassen würden. Als relevante kognitive Merkmale fungierten Maße zur verbalen und nichtverbalen Intelligenz und zum logischen Denken sowie Kompetenzen in den Bereichen Lesen, Rechtschreiben und Mathematik. Der Untersuchungszeitraum umfasste die Spanne zwischen dem Vorschulalter (4 Jahre) und dem späten Jugendalter (17 Jahre). Spätere Gymnasiasten und Hauptschüler definierten die beiden hier relevanten Gruppen intellektuell fähiger und weniger fähiger Probanden. In Übereinstimmung mit einer Vorläuferuntersuchung ( Schneider, Knopf & Stefanek, 2002 ) ließen sich wenig Anzeichen für differentielle Entwicklungsverläufe beim Vergleich beider Gruppen finden. Die postulierten Schereneffekte waren lediglich für die verbale Intelligenz, das formale Denken sowie die Rechtschreibleistung nachweisbar. Für alle anderen erfassten Merkmale galt, dass sich reliable Unterschiede zwischen späteren Gymnasiasten und Hauptschülern schon zum ersten Messzeitpunkt (also im Alter von 4 Jahren) fanden, die sich dann im weiteren Entwicklungsverlauf nicht mehr wesentlich veränderten. Der vermutete Einfluss unterschiedlicher pädagogischer Kontexte auf die intellektuelle Entwicklung konnte nur ansatzweise bestätigt werden.

Assessing cognitive outcomes in a rural African population: development of a neuropsychological battery in Kilifi District, Kenya

The ability to measure neuropsychological outcomes in a comparable manner in different cultural groups is important if studies conducted in geographically diverse regions are to advance knowledge of disease effects and moderating influences. The purpose of this study was to evaluate the application of neuropsychological test procedures developed for use in North America and Europe to children in a rural region of Kenya. Our specific aim was to determine if these methods could be adapted to a non-Western culture in a manner that would preserve test reliability and validity. Procedural modifications yielded reliable tests that were sensitive to both the sequelae of cerebral malaria and to children's social and school backgrounds. Results suggest that adaptations of existing tests can be made in such a way as to preserve their utility in measuring the cross-cultural sequelae of childhood neurological diseases.

Cast in Six Ponds and You'll Reel in Something: Looking Back on 25 Years of Research

The author describes his program of research over the past 25 years. This research falls into 6 areas that are interdependent and that inform each other. The overall program is guided by 3 bioecological principles that posit the need for proximal processes and motivation to actualize biological potential. The author presents examples of experiments that fall into each of the 6 areas and show that human potential is highly contextualized and that, consequently, the same person who fails at a task in one domain is often able to succeed at it in a different domain.

Effects of early childhood supplementation on the educational achievement of women

OBJECTIVE

Malnutrition during early childhood has been suggested to cause functional disadvantages in adults, including reduced intelligence and lower educational achievement (EA). We assessed the effects of improved nutrition in early life on the EA of women in 4 rural Guatemalan villages.

METHODS

The study sample comprised 130 female singletons exposed to either Atole (53%, 91 kcal and 6.4 g protein/100 mL) or Fresco (47%, 33 kcal/100 mL, no protein) during the prenatal period and the first 2 years of life. EA was assessed at the ages of 22 to 29 years by knowledge, numeracy, and several reading tests. A summary measure of EA was computed based on 5 tests, and outcome variables were categorized into quintiles. Analysis was based on a proportional odds model. Generalized estimating equations were used to account for sibling clustering.

RESULTS

Overall, 36.2% of women completed primary school. Women exposed to Atole had better EA than those exposed to Fresco (odds ratio [OR]: 2.8; 95% confidence interval [CI], 1.4, 5.4), with a significant treatment-by-schooling interaction. Atole was not associated with EA (OR: 1.5; 95% CI: 0.7, 3.2) among women who did not complete primary school, whereas among those who completed primary school, Atole was associated with improved EA (OR: 13.7; 95% CI: 3.7, 50.8).

CONCLUSIONS

We conclude that better nutrition during early childhood improved adult EA, but only among children who completed primary school.

Neural mechanisms of general fluid intelligence

We used an individual-differences approach to test whether general fluid intelligence (gF) is mediated by brain regions that support attentional (executive) control, including subregions of the prefrontal cortex. Forty-eight participants first completed a standard measure of gF (Raven's Advanced Progressive Matrices). They then performed verbal and nonverbal versions of a challenging working-memory task (three-back) while their brain activity was measured using functional magnetic resonance imaging (fMRI). Trials within the three-back task varied greatly in the demand for attentional control because of differences in trial-to-trial interference. On high-interference trials specifically, participants with higher gF were more accurate and had greater event-related neural activity in several brain regions. Multiple regression analyses indicated that lateral prefrontal and parietal regions may mediate the relation between ability (gF) and performance (accuracy despite interference), providing constraints on the neural mechanisms that support gF.

Complexities in Identifying and Defining Mathematics Learning Disability in the Primary School-Age Years

This paper is a descriptive report of findings from a prospective longitudinal study of math disability (MD). The study was designed to address the incidence of MD during primary school, the utility of different MD definitions, and evidence of MD subtypes. The results illustrate the dynamic properties of psychometrically derived definitions of MD. Different groups of children meet criteria for MD depending on which measure(s) are used for identification. Over time, a given individual may not continue to meet MD criteria, even when using the same assessments. Thus, the findings lead to cautions regarding the single-tool/ one-time assessment for a clinical diagnosis of MD. Twenty-two of 209 participants demonstrated "persistent MD" (MD-p), or MD for more than one school grade. Reading disability was relatively more frequent in this MD-p subgroup than in the remaining participants (25 percent vs. 7 percent). Reading-related skills were correlated with math achievement, as were select visual spatial skills. There was minimal overlap between groups who met either a "poor achievement" criteria or an "IQ-achievement discrepancy," and the latter was far less stable a measure over time than the former. The results highlight the complexities of defining MD and illustrate the need for more research in this area.

Bezugsnormorientierte Selbstkonzepte? Zur Eignung der SESSKO

Zusammenfassung: Die Eignung der neuen “Skalen zur Erfassung des schulischen Selbstkonzepts” (SESSKO; Schöne, Dickhäuser, Spinath & Stiensmeier-Pelster, 2002 ) wird an einer Stichprobe von Gymnasiasten (N = 907) überprüft. Die psychometrischen Kennwerte sind mit den im Manual angegebenen vergleichbar. Allerdings kann die von den Testautoren postulierte dimensionale Struktur des schulischen Selbstkonzepts - drei Skalen, die die Bezugsnormorientierungen “kriterial”, “sozial” und “individuell” thematisieren, sowie eine “absolute” Skala, die auf keine Bezugsnorm abzielt - nicht repliziert werden. Die “individuellen” Items bilden eine eigene Komponente; die übrigen Items fallen zu einer weiteren Mischkomponente zusammen. Psychologisch überzeugende differenzielle Validitätshinweise der vier theoretisch postulierten Selbstkonzeptskalen zu weiteren Selbstkonzeptfacetten, zu diversen Aspekten der Leistungsängstlichkeit, zu Schulleistungen und zu Interessen an Schulfächern sind nicht festzustellen.

When and where do we apply what we learn? A taxonomy for far transfer

Despite a century's worth of research, arguments surrounding the question of whether far transfer occurs have made little progress toward resolution. The authors argue the reason for this confusion is a failure to specify various dimensions along which transfer can occur, resulting in comparisons of "apples and oranges." They provide a framework that describes 9 relevant dimensions and show that the literature can productively be classified along these dimensions, with each study situated at the intersection of various dimensions. Estimation of a single effect size for far transfer is misguided in view of this complexity. The past 100 years of research shows that evidence for transfer under some conditions is substantial, but critical conditions for many key questions are untested.

Music and nonmusical abilities

Reports that exposure to music causes benefits in nonmusical domains have received widespread attention in the mainstream media. Such reports have also influenced public policy. The so-called "Mozart effect" actually refers to two relatively distinct phenomena. One concerns short-term increases in spatial abilities that are said to occur from listening to music composed by Mozart. The other refers to the possibility that formal training in music yields nonmusical benefits. A review of the relevant findings indicates that the short-term effect is small and unreliable. Moreover, when it is evident, it can be explained by between-condition differences in the listener's mood or levels of cognitive arousal. By contrast, the effect of music lessons on nonmusical aspects of cognitive development is still an open question. Several studies have reported positive associations between formal music lessons and abilities in nonmusical (e.g., linguistic, mathematical, and spatial) domains. Nonetheless, compelling evidence for a causal link remains elusive.

Heritability estimates versus large environmental effects: the IQ paradox resolved

Some argue that the high heritability of IQ renders purely environmental explanations for large IQ differences between groups implausible. Yet, large environmentally induced IQ gains between generations suggest an important role for environment in shaping IQ. The authors present a formal model of the process determining IQ in which people's IQs are affected by both environment and genes, but in which their environments are matched to their IQs. The authors show how such a model allows very large effects for environment, even incorporating the highest estimates of heritability. Besides resolving the paradox, the authors show that the model can account for a number of other phenomena, some of which are anomalous when viewed from the standard perspective.

The determinants of arithmetic skills in young children: some observations

The cause or causes of arithmetic difficulties in young children are manifold. The condition has its origins in a set of complex disorders and may be due to genetic factors, developmental delays, experiential limitations, language problems, and perceptual, motor, memory and other cognitive weaknesses. Other factors which may cause the disorder are inappropriate and ineffectual instructional practices. Anxiety and unfavourable attitudes towards the subject may influence mastery of arithmetic attainment in young children.

Severity and timing of stunting in the first two years of life affect performance on cognitive tests in late childhood

Undernutrition in infancy and early childhood is thought to adversely affect cognitive development, although evidence of lasting effects is not well established. With the use of data from the Cebu Longitudinal Health and Nutrition Study, we assesshere the relationship between stunting in the first 2 y of life and later cognitive development, focusing on the significance of severity, timing and persistence of early stunting. The sample included > 2000 Filipino children administered a cognitive ability test at ages 8 and 11 y. Stunting status was determined on the basis of anthropometric data collected prospectively between birth and age 2 y. Children stunted between birth and age 2 y had significantly lower test scores than nonstunted children, especially when stunting was severe. The shortfall in test scores among children stunted in the first 2 y was strongly related to reduced schooling, which was the result of a substantial delay in initial enrollment as well as higher absenteeism and repetition of school years among stunted children. Interactions between stunting and schooling were not significant, indicating that stunted and nonstunted children benefitted similarly from additional schooling. After multivariate adjustment, severe stunting at age 2 y remained significantly associated with later deficits in cognitive ability. The timing of stunting was also related to test performance, largely because children stunted very early also tended to be severely stunted (chi(2) P = 0.000). Deficits in children's scores were smaller at age 11 y than at age 8 y, suggesting that adverse effects may decline over time. Results emphasize the need to prevent early stunting and to provide adequate schooling to disadvantaged children.

A Person–Process–Context–Time Approach to Understanding Intellectual Development

We argue that scientific psychology's twin foci on biology (person) and process can benefit from a broadening. Specifically, we show that including two additional foci—context and time—can add explanatory leverage to both the design and interpretation of scientific studies. We focus on research on intellectual development to illustrate our points. First, we briefly describe each of the four factors (person, process, context, and time), and we review studies that focus on each individual factor and its role in intellectual development. Next, we review studies that focus simultaneously on multiple factors. We illustrate how multifactor approaches reveal fine-grained differentiations that are not reducible to single factors. Finally, we describe a study that considers simultaneously all four factors, and we show how omitting any one of these factors from the design and analysis changes the interpretation of the data.

The importance of intelligence in western societies

There are many different questions about intelligence that easily become confused. They concern its measurement, its psychological basis (if any), its heritability and its relevance to human group differences. Even a discussion of the importance of intelligence could range widely. (1) The evolution of intelligence might consider what selection pressures generate and maintain the higher levels of intelligence that humans are generally thought to possess. (2) The persistence of individual differences in human intelligence could consider whether such differences serve some ‘group’ function in establishing clear bases for social hierarchy: individuals might differ just because intelligence is irrelevant to fertility under conditions of social hierarchy. Or the differences might be temporary, because Western social hierarchies depend on intelligence differences that they will soon undermine. (3) Is intelligence an explanatory concept in psychology? Or must attribution of scholastic or other successes to ‘intelligence’ always yield to further analyses that somehow break down intelligence into hypothetical ‘components’? (4) Educational relevance might be the issue: is it important to take intelligence differences into account when deciding on how to educate children? (5) Or the concern might be with democratic sentiment and the importance people attach to intelligence for themselves and in their spouses and children.