Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jan van Leeuwe is active.

Publication


Featured researches published by Jan van Leeuwe.


Appetite | 2005

The Stice model of overeating: Tests in clinical and non-clinical samples

Tatjana van Strien; Rutger C. M. E. Engels; Jan van Leeuwe; Harriëtte M. Snoek

The present study tested the dual pathway model of Stice [. A review of the evidence for a sociocultural model of bulimia nervosa and an exploration of the mechanisms of action. Clinical Psychology Review, 14, 633-661 and . A prospective test of the dual-pathway model of bulimic pathology: mediating effects of dieting and negative affect. Journal of Abnormal Psychology, 110, 124-135.] in a non-clinical sample of female adolescents and a clinical sample of female eating disorder patients. The model assumes that negative affect and restrained eating mediates the link between body dissatisfaction and overeating. We also tested an extended version of the model postulating that negative affect and overeating are not directly related, but indirectly through lack of interoceptive awareness and emotional eating. Structural equation modelling was used to test our models. First, in the two samples, body dissatisfaction and drive for thinness were associated with overeating/binge eating. In both clinical and adolescent sample, we found support for the negative affect pathway and not for the restraint pathway. Lack of interoceptive awareness and emotional eating appear to (partly) explain the association between negative affect and overeating. Emotional eating was much more strongly associated with overeating in the clinical than in the adolescent sample. In sum, we found substantial evidence for the negative affect pathway in the dual pathway model. The link between body dissatisfaction and overeating in this respect might be explained by the fact that negative affect, due to body dissatisfaction, is related to a lack of awareness of personal feelings and to eating when dealing with negative emotions, which on its turn is associated with overeating.


Scientific Studies of Reading | 2011

Vocabulary Growth and Reading Development across the Elementary School Years

Ludo Verhoeven; Jan van Leeuwe; Anne Vermeer

The associations between vocabulary growth and reading development were examined longitudinally for a representative sample of Dutch children throughout the elementary school period. Data on basic and advanced vocabulary, word decoding, and reading comprehension were collected across the different grades. The results showed significant progress on all of the measures over time. The stability of the vocabulary measures was high, which shows a great deal of continuity in both the basic and advanced vocabularies of the children. Beginning vocabulary was found to predict early word decoding and reading comprehension as was predicted from the lexical restructuring hypothesis. From second grade on, word decoding predicted later vocabulary development. Moreover, a reciprocal relationship between the childrens advanced vocabulary and reading comprehension was detected. The data provide support for the lexical quality hypothesis as knowledge of word forms and word meanings predicts the development of reading comprehension.


Appetite | 2009

Possible pathways between depression, emotional and external eating. A structural equation model.

Machteld A. Ouwens; Tatjana van Strien; Jan van Leeuwe

Emotional and external eating appear to co-occur and both have been shown to correlate to neuroticism, especially depression. However, there is evidence suggesting that emotional and external eating are independent constructs. In this study we revisited the relation between depression, emotional, and external eating. Using structural equation modelling, we examined whether depression, emotional and external eating are directly related and also indirectly related through the intervening concepts alexithymia and impulsivity. Participants were 549 females concerned about their weight. They filled out instruments on emotional and external eating, depression, alexithymia, and impulse regulation. The relational structure between the model variables was explored for one half of the participants and this solution was checked using the other half. Our data showed a moderate relationship between emotional and external eating. Depression was positively and directly associated with emotional eating, but not with external eating. In addition, depression was indirectly related to emotional eating through both alexithymia and impulsivity. A significant relation was found between impulsivity and external eating. Results suggest potential mediating pathways between depression and emotional eating, while no relation appeared to exist between depression and external eating. Emotional and external eating would appear to be different constructs.


Appetite | 2007

Construct validation of the Restraint Scale in normal-weight and overweight females.

Tatjana van Strien; C. Peter Herman; Rutger C. M. E. Engels; Junilla K. Larsen; Jan van Leeuwe

The Restraint Scale (RS) is a widely used measure to assess restrained eating. The purpose of this study was to examine the construct validity of the RS in a sample of normal-weight (n=349) and overweight (n=409) females using confirmatory factor analyses of the RS in relation to other measures for dieting, overeating and body dissatisfaction. Following Laessle et al. [(1989a). A comparison of the validity of three scales for the assessment of dietary restraint. Journal of Abnormal Psychology, 98, 504-507], we assumed a three-factor structure: (1) overeating and disinhibitory eating, (2) dieting and restriction of food intake, and (3) body dissatisfaction and drive for thinness. Analyses revealed that the RS loaded significantly on all three factors for both samples, confirming its multifactorial structure. However, the RS appears to capture these constructs differently in overweight and normal-weight females such that the RS may overestimate restraint in overweight individuals. This may explain the greater effectiveness of the RS in predicting counter-regulation in normal-weight than in overweight samples of dieters.


Reading and Writing | 2001

Development of decoding, reading comprehension, vocabulary and spelling during the elementary school years

C.A.J. Aarnoutse; Jan van Leeuwe; Han Oud

The goal of this study was (1) to investigate the development of decoding(efficiency), reading comprehension, vocabulary and spelling during theelementary school years and (2) to determine the differences between poor,average and good performers with regard to the development of theseskills. Twice each year two standardized tests for each skill wereadministered. For two successive periods, one of the tests for each skill wasthe same. To describe the development in terms of a latent variable evolvingacross grades, the structured-means version of the structural equationmodel was used. The growth was expressed in terms of effect size. Withrespect to the first question, clear seasonal effects were found for readingcomprehension, vocabulary and spelling, while the seasonal effect fordecoding efficiency was restricted to the early grades. Progress tended tobe greater from fall to spring than from spring to fall. For decodingefficiency, and to a lesser degree for vocabulary and spelling, growthshowed a declining trend across grades. For reading comprehension, theprogress in grade 2 was lower than the progress in grade 3, but progresswas declining across higher grades. With respect to the second question,it appeared that initially low performers on reading comprehension,vocabulary and spelling tended to show a greater progress, especially inperiods where the largest amount of instruction was given. Although it wasfound that the low, medium and high ability groups remain in the sameorder, as far as their means are concerned, these findings do not confirmthe existence of a Matthew effect for reading comprehension, vocabularyand spelling. For decoding efficiency no clear differential effect could befound: the gap between the poor and good performers did not widen overtime for this skill.


Educational Research and Evaluation | 2005

Early Literacy From a Longitudinal Perspective

C.A.J. Aarnoutse; Jan van Leeuwe; Ludo Verhoeven

The goal of this longitudinal study was to examine which skills in early literacy determine the development of word recognition, reading comprehension, and spelling in the 2nd grade of the elementary school. A cohort of pupils was followed and tested during the 2nd year of kindergarten and the beginning of the 1st and 2nd grade. It appeared that mainly 2 skills determined the development of word recognition: rapid naming of letters and knowledge of letters. Reading comprehension was predicted to a large extent by vocabulary, rapid naming of letters, letter knowledge, and phonemic awareness. The skills that determined the development of spelling were rapid naming of numbers and letter knowledge.


Reading and Writing | 2012

The simple view of second language reading throughout the primary grades.

Ludo Verhoeven; Jan van Leeuwe

In the Simple View of Reading proposed by Hoover and Gough (1990), reading comprehension is conceived as the product of word decoding and listening comprehension. It is claimed that listening comprehension or the linguistic processes involved in the comprehension of oral language strongly constrain the process of reading comprehension. In several studies, evidence for this theoretical framework has been provided for first language learners. In the present study, an attempt was made to find empirical evidence for the same view underlying second language reading. Therefore, the word decoding and listening comprehension skills of samples of 1,293 first language (L1) learners and 394 second language (L2) learners of Dutch were related to their reading comprehension abilities throughout the primary grades. It was found that the levels of word decoding were more or less equal in the two groups of learners, whereas the L2 learners stayed behind their first L1 peers in both listening, and reading comprehension. The relationships between word decoding, listening comprehension and reading comprehension turned out to be highly comparable. A longitudinal analysis of data showed the Simple View of Reading to be equally valid for L1 and L2 learners. With progression of grade, the impact of word decoding on reading comprehension decreased, whereas the impact of listening comprehension showed an increase to the same extent in the two groups of learners. However, the reciprocity of the relationship between listening comprehension and reading comprehension tended to be less prominent in the group of L2 learners.


Scientific Studies of Reading | 2009

Modeling the Growth of Word-Decoding Skills: Evidence from Dutch.

Ludo Verhoeven; Jan van Leeuwe

This study investigated the growth of word-decoding skills throughout the elementary school years for a representative sample of 2,819 Dutch children. Childrens decoding abilities for (a) regular consonant-vowel-consonant words, (b) complex monosyllabic words with consonant clusters in prevocalic and postvocalic position, and (c) polysyllabic words were assessed on two occasions in each school year (Grades 1–6). The growth of word-decoding skills was found to be largely a matter of increased speed. Growth curve analyses showed a gradual curvilinear model to be superior to a step-model for all word-decoding skills. Furthermore, the three measures of word decoding define a common factor and show strong longitudinal stability. Some unique variance for the three word-decoding skills also emerged suggesting that the development of fully proficient word-decoding skills requires the learning of orthographic complexities.


Alcoholism: Clinical and Experimental Research | 2008

The Relative Contribution of Genes and Environment to Alcohol Use in Early Adolescents: Are Similar Factors Related to Initiation of Alcohol Use and Frequency of Drinking?

Evelien A. P. Poelen; Eske M. Derks; Rutger C. M. E. Engels; Jan van Leeuwe; Ron H. J. Scholte; Gonneke Willemsen; Dorret I. Boomsma

BACKGROUND The present study assessed the relative contribution of genes and environment to individual differences in initiation of alcohol use and frequency of drinking among early adolescents and examined the extent to which the same genetic and environmental factors influence both individual differences in initiation of alcohol use and frequency of drinking. METHODS Questionnaire data collected by the Netherlands Twin Register were available for 694 twin pairs aged of 12 to 15 years. Bivariate genetic model fitting analyses were conducted in mx. We modeled the variance of initiation of alcohol use and frequency of drinking as a function of three influences: genetic effects, common environmental effects, and unique environmental effects. Analyses were performed conditional on sex. RESULTS Findings indicated that genetic factors were most important for variation in early initiation of alcohol use (83% explained variance in males and 70% in females). There was a small contribution of common environment (2% in males, 19% in females). In contrast, common environmental factors explained most of the variation in frequency of drinking (82% in males and females). In males the association between initiation and frequency was explained by common environmental factors influencing both phenotypes. In females, there was a large contribution of common environmental factors that influenced frequency of drinking only. There was no evidence that different genetic or common environmental factors operated in males and females. CONCLUSION Different factors were involved in individual differences in early initiation of alcohol use and frequency of drinking once adolescents have started to use alcohol.


Nicotine & Tobacco Research | 2007

Factorial and Convergent Validity of Nicotine Dependence Measures in Adolescents: Toward a Multidimensional Approach

Marloes Kleinjan; Regina J. J. M. van den Eijnden; Jan van Leeuwe; Roy Otten; Johannes Brug; Rutger C. M. E. Engels

The present study investigated the possibility of forming a multidimensional scale for the measurement of nicotine dependence among adolescents, based on the modified Fagerström Tolerance Questionnaire (mFTQ) and the Hooked on Nicotine Checklist (HONC). A survey was conducted among 33 Dutch secondary schools, resulting in 2,041 smokers who completed the questionnaire. Motivation to quit and number of quit attempts were assessed and used as convergent construct variables for the construct of nicotine dependence. The findings show that combining the items of the mFTQ and the HONC results in three distinct dimensions: behavioral aspects of nicotine dependence, craving, and nervousness during abstinence. We examined this new multidimensional model in a second sample using confirmatory factor analysis. The new multidimensional measure fitted the data satisfactorily and showed good psychometric properties. Results of this study support the notion that nicotine dependence among adolescents is multidimensional.

Collaboration


Dive into the Jan van Leeuwe's collaboration.

Top Co-Authors

Avatar

Ludo Verhoeven

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

C.A.J. Aarnoutse

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar

Tatjana van Strien

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar

Johannes Brug

VU University Medical Center

View shared research outputs
Top Co-Authors

Avatar

Marloes Kleinjan

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar

Silvia Morales Silva

Pontifical Catholic University of Peru

View shared research outputs
Top Co-Authors

Avatar

Hans van Balkom

Radboud University Nijmegen

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge