Behavioural genetics in the 21st century

Continuity and change of genetic and environmental influences on reading and reading-related neurocognitive skills: A systematic review of longitudinal twin studies

Learning to read is a dynamic and cumulative process beginning from birth and continuing through the school years. Empirical data showed a decrease of additive genetic (A) and shared environmental (C) components and an increase of non-shared environmental (E) components from preschool to middle school. However, our understanding of the aetiology of continuity and change of reading skills across this developmental period is limited. Following the PRISMA guidelines, we reviewed the results of behavioral genetic research on reading-related neurocognitive skills of 13 longitudinal twin and adoptive sibling studies spanning from preschool/kindergarten to middle/high school. Our findings suggested that continuity was mainly explained by A components throughout the study periods, and, although to a lesser extent and less consistently, by C components during the early years; change was explained by new E components throughout the years, and also by new A components in the early years. As we are interested in models relevant to traits with early onset during development, it is crucial to deepen the investigation of how developmental time can moderate the genetic and environmental variation.

The heritability of reading and reading-related neurocognitive components: A multi-level meta-analysis

Reading ability is a complex task requiring the integration of multiple cognitive and perceptual systems supporting language, visual and orthographic processes, working memory, attention, motor movements, and higher-level comprehension and cognition. Estimates of genetic and environmental influences for some of these reading-related neurocognitive components vary across reports. By using a multi-level meta-analysis approach, we synthesized the results of behavioral genetic research on reading-related neurocognitive components (i.e. general reading, letter-word knowledge, phonological decoding, reading comprehension, spelling, phonological awareness, rapid automatized naming, and language) of 49 twin studies spanning 4.1-18.5 years of age, with a total sample size of more than 38,000 individuals. Except for language for which shared environment seems to play a more important role, the causal architecture across most of the reading-related neurocognitive components can be represented by the following equation a² > e² > c². Moderators analysis revealed that sex and spoken language did not affect the heritability of any reading-related skills; school grade levels moderated the heritability of general reading, reading comprehension and phonological awareness.

Contribuições das teorias do desenvolvimento humano para a concepção contemporânea da adolescência

O interesse pelo estudo da adolescência vem aumentando, sobretudo por seu impacto no desenvolvimento do indivíduo, da família e da sociedade. Tratar a adolescência simplesmente como um período de grandes mudanças não condiz com as atuais perspectivas teóricas da ciência do desenvolvimento. Portanto, este artigo visa contribuir para uma compreensão mais atualizada deste período do curso de vida, caracterizado por intensa exploração e múltiplas oportunidades, que variam em função dos diferentes contextos sociais e culturais. Ênfase é dada à importância de se adotar um paradigma sistêmico para a compreensão da adolescência, priorizando as inter-relações dos recursos individuais e contextuais que promovem as trajetórias de desenvolvimento positivo.

As contribuições da ciência do desenvolvimento para a psicologia da saúde

A ciência do desenvolvimento humano vem estimulando uma nova visão sobre a pesquisa em saúde, destacando variáveis contextuais e ecológicas que influenciam o processo de desenvolvimento e condicionam o diagnóstico, o tratamento e o prognóstico de indivíduos e grupos. O objetivo deste artigo é discutir as implicações da ciência do desenvolvimento humano à psicologia da saúde, área de intervenção educacional voltada aos diversos contextos de tratamento de saúde. Pretende-se, ainda, analisar criticamente alguns aspectos metodológicos dos estudos da área e apontar tendências atuais e futuras para uma análise mais funcional do processo saúde-doença. Espera-se que os profissionais de saúde se beneficiem dos argumentos e modelos propostos pela ciência do desenvolvimento humano, construindo ambientes de cuidados mais adequados às necessidades psicossociais de pacientes e familiares.

Genes, cognition, and communication: insights from neurodevelopmental disorders

Twin and family studies have demonstrated that most cognitive traits are moderately to highly heritable. Neurodevelopmental disorders such as dyslexia, autism, and specific language impairment (SLI) also show strong genetic influence. Nevertheless, it has proved difficult for researchers to identify genes that would explain substantial amounts of variance in cognitive traits or disorders. Although this observation may seem paradoxical, it fits with a multifactorial model of how complex human traits are influenced by numerous genes that interact with one another, and with the environment, to produce a specific phenotype. Such a model can also explain why genetic influences on cognition have not vanished in the course of human evolution. Recent linkage and association studies of SLI and dyslexia are reviewed to illustrate these points. The role of nonheritable genetic mutations (sporadic copy number variants) in causing autism is also discussed. Finally, research on phenotypic correlates of allelic variation in the genes ASPM and microcephalin is considered; initial interest in these as genes for brain size or intelligence has been dampened by a failure to find phenotypic differences in people with different versions of these genes. There is a current vogue for investigators to include measures of allelic variants in studies of cognition and cognitive disorders. It is important to be aware that the effect sizes associated with these variants are typically small and hard to detect without extremely large sample sizes.

Positive youth development: thriving as the basis of personhood and civil society

Positive youth development is conceptualized within a developmental systems theoretical model. The role of thriving processes and civic engagement in positive youth development is discussed.

Contemporary developmental theory and adolescence: developmental systems and applied developmental science

PURPOSE

To discuss developmental systems models of human development and explain how they offer a productive frame for research, policies, and programs aimed at understanding adolescents' development and enhancing their health and positive development. Contemporary developmental theory stresses that the multiple levels of organization involved in human life (ranging from biology through culture, the natural and designed ecology, and history) are systemically integrated across ontogeny. Relations within this developmental system are the focus of developmental analysis and application.

METHODS

The key features of developmental systems theories are reviewed, and their use for framing scholarship about and applications for improving adolescent development are assessed.

RESULTS

We demonstrate the potential of contemporary developmental theory for understanding the character and dynamics of adolescent development and for using this knowledge for the design of effective policies and programs that promote positive youth development.

CONCLUSIONS

An adequate and sufficient science of adolescent development, and one that is able to help in the development of successful policies and programs for youth, must integratively study the relations between individuals and contexts in an integrated, systemic, and temporal manner.