Rural, tropical coastal communities are experiencing sustained, often increasing food insecurity, poverty, and global change impacts. These challenges have stimulated a rise in projects aiming to... Show moreRural, tropical coastal communities are experiencing sustained, often increasing food insecurity, poverty, and global change impacts. These challenges have stimulated a rise in projects aiming to enhance and diversify local livelihoods. The ability of these projects to achieve broad-scale benefits is limited by approaches that do not account for feedbacks among sectors and across marine and terrestrial environments. To address these limitations, we present an applied research agenda to support an integrated approach to livelihood project planning and management. This agenda explicitly examines interactions among natural resources, industries, and livelihoods and is based on three foundational activities: (1) a governance review and assessment, (2) strategic partnership formation, and (3) a diagnostic approach supported by science and shared outcomes. We add structure to the established logic in our field by broadening the sectoral and spatial scope of livelihoods projects, so they can better contribute to interrelated UN Sustainable Development Goals. Show less
The overarching goal of this thesis was to examine the behavioral, computational, and neural mechanisms underlying social learning in adolescence. The first aim was to examine developmental... Show moreThe overarching goal of this thesis was to examine the behavioral, computational, and neural mechanisms underlying social learning in adolescence. The first aim was to examine developmental patterns across adolescence of two forms of social learning: (1) learning about other people, specifically, whether they are (un)cooperative and (un)trustworthy, and (2) learning for other people (prosocial learning) to know what actions may benefit or help others. I made use of multiple experimental paradigms based on well-known economic games and/or probabilistic reinforcement learning paradigms to assess these forms of social learning. Secondly, I aimed to examine underlying mechanisms and factors that account for age-related and individual differences in social learning. Applying computational modeling and functional neuroimaging as additional tools contributed to a better understanding of the underlying mechanisms and how these develop across adolescence. The findings in this thesis converge to early-to-mid adolescence as a key developmental period for developing well-adjusted social behaviors, and especially in the cooperative domain there are pronounced improvements. These studies make an important contribution to the literature on social development and learning, and may eventually contribute to interventions targeted at promoting well-adjusted behavior in typically developing adolescents, as well as youth with maladaptive social tendencies. Show less
This thesis investigated the development of emotional functioning in 2-to-6-year-old children with and without autism. Whereas autistic children experienced more challenges in the emotional domain,... Show moreThis thesis investigated the development of emotional functioning in 2-to-6-year-old children with and without autism. Whereas autistic children experienced more challenges in the emotional domain, their emotional abilities improved with age, and developed in similar ways as observed in non-autistic children. On the one hand, this thesis showed that autistic children might deal with emotions in a different way, and they might experience various difficulties when communicating emotions with non-autistic people. One the other hand, it is important to note that the difficulties could be bidirectional. As stated by the “double empathy problem”, non-autistic people may experience the same difficulties when communicating with autistic people. This could be a meaningful direction for future research, investigating emotional communication as a two-way interaction rather than focusing only on how people with autism react to people without autism. Furthermore, this thesis showed that autistic children had the potential to learn and to develop in the emotional domain. Again, this points to the importance of investigating how to create an inclusive social environment, which is not only nurturing for children without autism, but can also benefit the development of children with autism and with other special needs. Show less
Klapwijk, E.T.; Van de Kamp, F.; Meulen, M. van der; Peters, S.; Wierenga, L.M. 2019
Adolescence has been described as a unique period for self-concept development, with an intensified alertness to social comparison as a mechanism for self-knowledge and self-evaluation. However, it... Show moreAdolescence has been described as a unique period for self-concept development, with an intensified alertness to social comparison as a mechanism for self-knowledge and self-evaluation. However, it remains difficult to disentangle the specific influence of these social comparisons on the development of self-descriptions in adolescence. Moreover, it is still unclear how social comparisons impact upon the development of self-views in different domains, such as physical, academic and social self-views. The goal of this study was therefore to examine the development of self-descriptions in different domains across adolescence, and to experimentally test how the development of these self-descriptions is altered by an explicit social comparison context. For this purpose, we developed two tasks which both asked participants (aged 9-25-years, N = 202) for trait self-descriptions but differed in the salience of a social comparison. Results showed consistent age-differences with more positive self-views for children and adolescents in the age-range 9–14 years. The context of explicit social comparison yielded similar as well as additional age-differences that were more dependent upon valence and domain. Moreover, mid-adolescents (15–17 y) were most negatively affected by these social comparisons relative to other ages. Together, this study made a first step in disentangling the specific influence of social comparison outcomes within the development of general self-descriptions, and highlights the importance of social context in studying self-concept in adolescence. Show less
There has been a large spike in longitudinal fMRI studies in recent years, and so it is essential that researchers carefully assess the limitations and challenges afforded by longitudinal designs.... Show moreThere has been a large spike in longitudinal fMRI studies in recent years, and so it is essential that researchers carefully assess the limitations and challenges afforded by longitudinal designs. In this article, we provide an overview of important considerations for longitudinal fMRI research in developmental samples, including task design, sampling strategies, and group-level analyses. We first discuss considerations for task designs, weighing the pros and cons of many commonly used tasks, as well as outlining how the tasks may be impacted by repeated exposure. Secondly, we review the types of group-level analyses that can be conducted on longitudinal fMRI data, analyses which must account for repeated measures. Finally, we review and critique recent longitudinal studies that have emerged in the past few years. Show less
Constructing a knowledge representation from multiple texts requires the integration of information across texts. The aim of the current study was to investigate how elementary school students... Show moreConstructing a knowledge representation from multiple texts requires the integration of information across texts. The aim of the current study was to investigate how elementary school students integrate information across multiple text passages and, particularly, whether students use information from a prior text to improve understanding of a current text. A sample of 105 children in grades 4 and 6 participated in the experiment. The multiple-text integration paradigm was used to study integration processes across texts during reading. Recall and (application) questions were used to investigate the extent to which information from different text passages was integrated into knowledge representations after reading. Individual differences in reading comprehension ability and working memory were also considered. The results indicate that children in both grades spontaneously activate information from an earlier text to aid their understanding during reading, and that they integrate information across texts in their knowledge representations. This was the case regardless of grade or individual differences in reading-comprehension ability and working memory. These findings provide insight into the mechanisms that may be involved in the integration of information across texts. Show less
Many hunter-gatherer groups live on the outskirts of wider society, experiencing poor health outcomes with little access to medical care. From a development perspective, key interventions include... Show moreMany hunter-gatherer groups live on the outskirts of wider society, experiencing poor health outcomes with little access to medical care. From a development perspective, key interventions include the sedentarisation of these mobile peoples into camps nearby larger towns with sanitation infrastructure and medical care, as increased access to services is assumed to improve outcomes. However, recent research in the Agta (Philippine foragers from North-east Luzon) has demonstrated that individuals residing in more ‘developed’ communities suffer from increased morbidity and mortality. Here, using quantitative and ethnographic data on health collected between 2002 and 2014, we explore why this trend occurs by examining the relationship between key development initiatives with self-reported illness and the uptake of medical interventions with 415 Agta men, women and children. We demonstrate that health outcomes worsen as sedentarisation progresses, despite some increases in medical access. We argue this is because the development paradigm is not evidence-based, but rather stems from an ideological dislike of mobile hunter-gatherer lifestyles. Compounded by cultural insensitivity and daily discrimination, current interventions are ill-suited to the unique needs of hunter-gatherers, and thus ineffective. Based on our findings we offer future short and long-term policy suggestions which seek to reduce the Agta's vulnerability, rather than increase it. Show less
Van der Cruijsen, R.; Peters, S.; Aar, L.P.E. van der; Crone, E.A. 2018
Neuroimaging studies in adults showed that cortical midline regions including medial prefrontal cortex (mPFC) and posterior parietal cortex (PPC) are important in self-evaluations. The goals of... Show moreNeuroimaging studies in adults showed that cortical midline regions including medial prefrontal cortex (mPFC) and posterior parietal cortex (PPC) are important in self-evaluations. The goals of this study were to investigate the contribution of these regions to self-evaluations in late childhood, adolescence, and early adulthood, and to examine whether these differed per domain (academic, physical and prosocial) and valence (positive versus negative). Also, we tested whether this activation changes across adolescence. For this purpose, participants between ages 11–21-years (N = 150) evaluated themselves on trait sentences in an fMRI session. Behaviorally, adolescents rated their academic traits less positively than children and young adults. The neural analyses showed that evaluating self-traits versus a control condition was associated with increased activity in mPFC (domain-general effect), and positive traits were associated with increased activity in ventral mPFC (valence effect). Self-related mPFC activation increased linearly with age, but only for evaluating physical traits. Furthermore, an adolescent-specific decrease in striatumactivation for positive self traits was found. Finally, we found domain-specific neural activity for evaluating traits in physical (dorsolateral PFC, dorsal mPFC) and academic (PPC) domains. Together, these results highlight the importance of domain distinctions when studying self-concept development in late childhood, adolescence, and early adulthood. Show less
Mensen, V.T.; Wierenga, L.M.; Dijk, S. van; Rijks, Y.; Oranje, B.; Mandl, R.C.W.; Durston, S. 2017
Children and adolescents who are chronically rejected by their peers suffer from widespread impairments in daily life, ranging from poor academic achievement and dropping out of school, to... Show moreChildren and adolescents who are chronically rejected by their peers suffer from widespread impairments in daily life, ranging from poor academic achievement and dropping out of school, to delinquency and the development of mental health problems. To gain a better understanding of the developmental processes that give rise to such impairments, the research described in this dissertation examined the neurocognitive underpinnings of processes that play a role in the emergence and maintenance of peer group rejection and acceptance. The first part of this dissertation focuses on neurocognitive processes underlying reactions to social exclusion. The second part concentrates on the neurocognitive processes involved in sharing valuable resources, based on the widely established finding that frequent displays of prosocial behaviors, such as cooperating, helping, and sharing, are associated with both gaining and maintaining acceptance among peers. The empirical work in this dissertation demonstrates that a developmental cognitive neuroscience approach provides unique insights into the emotional, regulatory, and socio-cognitive processes thought to play a role in the emergence and maintenance of peer group acceptance and rejection. Show less
Self-control abilities are crucial for successful functioning in daily life. At the core of self-control lies the ability to intentionally inhibit one__s actions. Intentional inhibition differs... Show moreSelf-control abilities are crucial for successful functioning in daily life. At the core of self-control lies the ability to intentionally inhibit one__s actions. Intentional inhibition differs from externally driven inhibition in that it is driven by an internal thought process rather than an external stimulus that tells one to stop. The goal of this thesis was to examine the development of intentional inhibition and compare this with externally driven inhibition. In order to investigate the covert process of intentional inhibition, the research described in this thesis made use of neurobiological measures such as phasic heart rate changes and functional magnetic resonance imaging (fMRI). In addition, to learn more about self-control in context, the final empirical chapter examined intentional and externally driven inhibition in the context of relevant and irrelevant emotions. Show less
We examined the development of international adoptees from infancy to young adulthood, and factors influencing developmental outcomes in middle childhood, adolescence and young adulthood. The... Show moreWe examined the development of international adoptees from infancy to young adulthood, and factors influencing developmental outcomes in middle childhood, adolescence and young adulthood. The results for cognitive development (Chapter 2) showed that early malnutrition influenced cognitive and health-related outcomes, but its consequences did not extend to socioeconomic success later in life. The human brain seems capable of adapting to changing environmental influences, but earlier placement in a positive family environment should be preferred (see also Chapter 1). The adoptees in the Leiden Longitudinal Adoption Study were exposed to few adversities due to their early adoptive placement, and the combination with the nurturing environment of a permanent adoptive family resulted in positive cognitive and socio-emotional outcomes (Chapters 2 and 3). Our results for longitudinal (sensitivity) and concurrent relations (reactivity to infant crying) with attachment representations in young adulthood (Chapters 3 and 4) clearly point to this role of the family environment in predicting social-emotional outcomes. High parenting quality is important, also in families where children do not share a common genetic basis with their parents. In sum, adoption can be seen as a positive intervention and the (adoptive) family environment matters for children growing up from infants to young adults. Show less
Core deficits in people with autisme spectrum disorders (ASD) are difficulties in adapting their behaviour to the social environment which hampers the possibilities to communicate adequately and to... Show moreCore deficits in people with autisme spectrum disorders (ASD) are difficulties in adapting their behaviour to the social environment which hampers the possibilities to communicate adequately and to have reciprocal relationships. These problems have a serious impact on functioning in their daily life. Since ASD are severe and lifelong conditions, it is relevant to examine how children with ASD develop troughout their life and to investigate which factors constitute an unfavourable contribution to their development. This thesis reveals that children with ASD are at specific risk of poor quality of life in adulthood when compared to children with other psychiatric disorders. Secondly, the impact of ASD on specific domains of intellectual functioning is different at different ages, implicating that re-evaluation of cognitive function during development of children with ASD is recommended during their life. Thirdly, children with ASD who are at risk of schizophrenia spectrum pathology, may show negative schizotypal symptoms, but also disorganized and positive symptoms in addition to ASD symptomatology. These symptoms of schizotypy appear to be associated with inhibition problems. We should be aware of inhibition problems in children with ASD because they may be indicators of high risk to schizophrenia spectrum pathology later in life. Show less
This thesis shows the final results of a longitudinal project where the same participants (12 to 15 yrs.) were followed for three consecutive years. The first objective of this study was to... Show moreThis thesis shows the final results of a longitudinal project where the same participants (12 to 15 yrs.) were followed for three consecutive years. The first objective of this study was to investigate the development of both quantity and quality of metacognitive skills. The second objective was to establish whether the development of metacognitive skills is intelligence-related or relatively intelligence-independent. Finally, the generality vs. domain-specificity of developing metacognitive skills was investigated. While thinking aloud, participants performed two different tasks representing two different domains: A text-studying task and a problem-solving task. Participants__ intellectual ability was assessed, as well as their metacognitive skills and learning performance for both domains separately. In summary, this thesis has shown that (1) Metacognitive skills do increase spontaneously in frequency and quality during young adolescence, albeit not continuously. The various subscales of metacognitive skillfulness do not develop at the same pace; (2) Metacognitive skills have their own contribution to the prediction of learning performance, on top of intellectual ability. The relation between intellectual ability and metacognitive skills as predictors of learning performance is not affected by development between 12 and 15 yrs.; (3) Around the age of 15 yrs. metacognitive skills become fully general. Show less
It is well known that complex mental abilities develop at least until late adolescence. Yet, there are also skills that children master perfectly, sometimes even better than adults. The goal of... Show moreIt is well known that complex mental abilities develop at least until late adolescence. Yet, there are also skills that children master perfectly, sometimes even better than adults. The goal of this thesis was to learn more about the possibilities of cognitive functioning in children and young adults, and the constraints set by the developing brain. An fMRI training approach was used to examine age- and experience-related effects in the development of working memory and resting-state functional connectivity. More specifically, we studied age differences on task performance and brain activation during a working memory task with various demands and difficulty levels, both before and after 6 weeks of practice with the task. In addition, to learn more about the interaction between different brain regions, we also examined age differences and practice effects on functional connectivity during resting-state. Show less
School refusal is an attendance problem characterized by a young person’s difficulty in going to school, accompanied by emotional distress on the part of the young person and parental attempts to... Show moreSchool refusal is an attendance problem characterized by a young person’s difficulty in going to school, accompanied by emotional distress on the part of the young person and parental attempts to return the young person to regular school attendance. Prolonged absence from school has serious short- and long-term consequences for young people, their families, and schools. Therefore, effective treatment of school refusal is essential. Numerous treatment outcome studies provide evidence for the efficacy of cognitive-behavioural therapy (CBT) for school refusal. Previous research has however indicated that adolescent school refusers may be particularly disturbed and harder to treat. An existing treatment for school-refusing children and adolescents was modified to better account for the impact of developmental variables on engagement in treatment. The studies presented in this dissertation describe the preparation, implementation, and evaluation of the resulting developmentally-appropriate CBT for adolescent school refusal. The treatment was associated with increased school attendance, reduced emotional symptoms, and increased adolescent and parental self-efficacy. Exploratory analyses revealed that several developmental factors were related to treatment outcomes, namely clinician developmental appropriateness, insight, and autonomy. Recommendations for research and clinical practice are made on the basis of these findings, and on the methodological strengths and limitations of the current research. Show less
