The similarity of siblings' attachments to their mother

Do siblings develop similar attachment relationships with their mother? Attachment theory suggests that brothers and sisters growing up in the same family are likely to relate in similar ways to their parents, at least when parental attachment representations and interactive styles remain stable across time. In the current study, sibling attachment data from three research groups (from Pennsylvania State University, Leiden University, and the University of Western Ontario) have been pooled to assemble a sufficiently large sample of observations (N = 138 sibling pairs) for a detailed comparison of sibling attachment relationships. Spacing between the births, differences in maternal sensitivity, and gender of siblings were examined as possible sources of concordance of nonconcordance. Attachment security (including disorganized attachment) of each sibling was assessed with the Strange Situation procedure between 12 and 14 months after birth. Maternal sensitivity was observed with the same rating scale in a laboratory play session in one of the studies and in home observations in the others. Sibling relationships were found to be significantly concordant when classified as secure/nonsecure (62% concordance, p < .01, 1-tailed, intraclass correlation = .23) but not when further subcategorized. Maternal insensitivity to both siblings (shared environment) was associated with concordance of sibling nonsecurity. Siblings of the same gender were more likely to form concordant relationships with their mother (68%; p < .01, 1-tailed, intraclass correlation = .37) than those of opposite gender. Same-sex sibling concordance was comparable to the concordance found for monozygotic twins in earlier studies. Genetic factors may, therefore, play a relatively small role in the development of attachment.     

Burning,Fluttering, and Extinguishing of a Candle Flame in a Tube

In this article, we report some experimental results on the behaviour of the flame of a candle kept at the bottom of a glass tube, which is open at the top and closed at the bottom. Thus, the supply of oxygen for the continuous burning of the flame is possible only from the top open end of the tube. We find that the candle burns steadily below a critical tube height. Above this height, the flame oscillates in size, and a further increase in tube height leads to the flame extinguishing quickly.     

¿Cómo desarrollar secuencialmente el conocimiento fonológico?

A partir de una revisión de los procesos que requiere la “conciencia fonológica”, necesaria para la lectura, se proponen aquí una serie de actividades para desarrollarla.     

Comprensión de la inclusion jerárquica de clases Estudio evolutivo

Resumen

En el presente trabajo se estudia el desarrollo de la comprensión de los principios que rigen la inclusión jerárquica de clases en sujetos de 4 a 14 años. Se presentan y comparan los resultados de tres experimentos en los que se utilizan, respectivamente, cuestiones de tipo piagetiano, problemas deductivos y problemas de inclusión con los cuantificadores «todos» y «algunos». Se examina también el efecto que diferentes variables definitorias de la estructura de las tareas tienen en el éxito o el fracaso en las mismas. Los resultados sugieren un desarrollo lineal progresivo en relación con la comprensión de la extensión diferente de clase y subclase, y la aplicación correcta de los cuantificadores, y un salto entre los 9 y 12 años en relación con la comprensión de la transitividad. Se discuten las implicaciones teóricas y prácticas de estos resultados.     

Prediction of academic achievement with the McCarthy screening test and metropolitan readiness test

There is a need for accurate, efficient assessment of children's readiness, to provide information concerning strengths and weaknesses of children and to identify those children who may be at risk for school failure. This necessitates determining the relative usefulness of instruments in predicting later school achievement. This study examined the efficacy of the McCarthy Screening Test (MST) and Metropolitan Readiness Test (MRT) to predict academic readiness at the end of kindergarten and achievement at the end of first grade. Eighty-eight children were screened upon entering kindergarten, using the MST. As a measurement of academic readiness, the MRT was administered at the end of kindergarten, and the Scott and Foresman Achievement Test (SFAT) was administered at the end of first grade as a measure of achievement. Regression analyses indicated that the MST significantly predicted children's scores on the MRT and SFAT. Additionally, the MRT was a significant predictor of the SFAT.