A standard interpretation of the coefficient of correlation may be obtained from the ratio of two variances. If it is assumed that two variables, X and Y, are bivariate normal and scaled to have zero means and unit variances, it can be shown that the correlation between X and Y is the ratio of two conditional means. Galton's statistical studies of…

Reviewed are chromosomal anomalies affecting one's eyes. Brief descriptions are given of the genetic etiology of bilateral retinoblastoma (malignant tumors), aniridia (absence of the iris), cataracts, congenital glaucoma, Reginitis Pigmentosa (progressive deterioration of the visual cells), Choroidermia (degeneration of the vascular coat of the…

A study of Kagan's peer play situation for measuring heritable influences on children's behavioral inhibition (that is, shyness) drew its data from the large, multimethod, multivariate MacArthur Longitudinal Twin Study. The MacArthur study examined behavioral inhibition across four ages and two situations, looking for possible sex differences and…

Explores the interplay between nature and nurture using antisocial behavior as the example, and discusses key genetic concepts and key environmental concepts. The final section considers the nature-nurture interaction in relation to passive, evocative, and active gene-environment correlations and calls for research into the effects of the…

Four studies investigated children's explanations for family resemblance and species-typical characteristics, under different conditions of biological parentage and rearing environment. Participating were 226 children between 3 and 11 years. Children Children were presented with a number of different tasks, some involving people and some domestic…

The modern history of biology shows how Darwin's selectionist theory has replaced instructionist theories in explaining the operations of living things: first with inheritance through the gene pool of the 1850s, and second with the replacement of a template theory of immune system function in the 1960s. Today scholars in several disciplines…

A Study was conducted to test the hypothesis proposed by J. S. Symmes and J. L. Rapoport that a sex-linked recessive gene might account for the good spatial ability found among dyslexic readers, the familial pattern of the disorder, and the frequently reported sex ratio of three affected males to one female. Spatial/reasoning ability scores were…

A proper understanding of the role of culture in development can make a significant contribution to the development of theory and offer a more certain guide to practice than current theories afford. Three frameworks for interpreting the influence of nature and nurture on individual development assign biological and environmental factors a direct…

There are two kinds of hereditary influence, genetic inheritance and biological inheritance, that may respond to environmental determinants. The ability to speak is one genetically produced aspect of being human, and research studies based on the assumption that speech is innate to humans have found that infants appear to pay particular attention…

This study examining children's understanding of biological inheritance addressed four central questions: (1) are young children able to distinguish between the relative influences of nature and nurture in their understanding of how physical characteristics versus behaviors and preferences develop in animals? (2) does children's understanding of…

Research has shown that differences among ordinary people in intelligence and personality depend equally on individual genetic variability and on differences in the environments that siblings experience within the same family, not differences in the neighborhood, school, and community environments. As of yet, there are no adequate theories to…

The estimation of genetic models reported by J. L. Jinks and L. J. Eaves in a recent review are critically examined. A number of errors in procedure and interpretation are found. It is concluded that the evidence, provided by kinship correlations, for the proposition that intelligence is highly heritable, is not persuasive. (Author/BJG)

There is increasing acceptance of the premise that growth and development continue throughout adult life and, as life expectancy has lengthened, there is a much expanded mid-life period. Yet, middle adulthood has been neglected as an area of theoretical and empirical examination. Adults (N=251) in middle adulthood (age 35-55) completed instruments…

This paper reviews the case of Carrie Buck, who was the first person sterilized (in 1927) under a Virginia law allowing sterilization of persons identified as incompetent and likely to genetically transmit physical, psychological, or social deficiencies to their offspring. This law was later upheld by the Supreme Court in Buck v. Bell, which…

Discusses the increasing significance of genetic diseases and defects in our lives and the social, moral-ethical, and legal problems resulting from medical genetics. (Author/SA)