La importancia de las emociones en los períodos sensibles del desarrollo = The importance of emotions in sensitive developmental periods

Investigaciones recientes sugieren que en la adolescencia tienen lugar importantes cambios en la estructura, bioquímica y fisiología del cerebro que podrían explicar la dificultad que experimentan los adolescentes en el control de sus emociones así como también otros rasgos de su comportamiento inestable. En este artículo presentamos algunas investigaciones que establecen, asimismo, una correlación entre las reorganizaciones cerebrales que tienen lugar en el primer año de vida con signos de irritabilidad y desazón emocional que muestra el bebé durante este periodo. En ambos casos la dificultad de controlar los impulsos emocionales es susceptible de afectar la relación de los padres con el niño o joven. Discutimos la posible relevancia de esta coincidencia dentro de una perspectiva evolucionista así como la posible vulnerabilidad de estos períodos. Finalmente, apuntamos la necesidad de una teoría integradora del desarrollo humano y ofrecemos algunos puntos de debate

Relationships between adolescents and parents values and parents answering behaviour

In this paper we set out a confirmatory factor analysis model relating the values adolescents and their parents aspire to for the child’s future. We approach a problem when collecting parents’ answers and analysing paired data from parents and their child: the fact that in some families only one parent answers, while in others both meet to answer together. In order to account for differences between one-parent and two-parent responses we follow a multiple group structural equation modelling approach. Some significant differences emerged between the two and one answering parent groups. We observed only weak relationships between parents’ and children’s values

A new distribution on the simplex containing the Dirichlet family

The Dirichlet family owes its privileged status within simplex distributions to easyness of interpretation and good mathematical properties. In particular, we recall fundamental properties for the analysis of compositional data such as closure under amalgamation and subcomposition. From a probabilistic point of view, it is characterised (uniquely) by a variety of independence relationships which makes it indisputably the reference model for expressing the non trivial idea of substantial independence for compositions. Indeed, its well known inadequacy as a general model for compositional data stems from such an independence structure together with the poorness of its parametrisation. In this paper a new class of distributions (called Flexible Dirichlet) capable of handling various dependence structures and containing the Dirichlet as a special case is presented. The new model exhibits a considerably richer parametrisation which, for example, allows to model the means and (part of) the variance-covariance matrix separately. Moreover, such a model preserves some good mathematical properties of the Dirichlet, i.e. closure under amalgamation and subcomposition with new parameters simply related to the parent composition parameters. Furthermore, the joint and conditional distributions of subcompositions and relative totals can be expressed as simple mixtures of two Flexible Dirichlet distributions. The basis generating the Flexible Dirichlet, though keeping compositional invariance, shows a dependence structure which allows various forms of partitional dependence to be contemplated by the model (e.g. non-neutrality, subcompositional dependence and subcompositional non-invariance), independence cases being identified by suitable parameter configurations. In particular, within this model substantial independence among subsets of components of the composition naturally occurs when the subsets have a Dirichlet distribution