Coming to terms with heritability

The complex mechanisms of heredity are little appreciated by non-specialists, in some measure, because of misunderstandings that are perpetuated when words used for technical terms have other, more widely understood, folk meanings. When a word has both technical and folk meanings, it is the responsibility of the specialist to avoid promoting confusion by either using extremely cautious and precise language when using the term or, in cases when confusion is inevitable, abandoning the term in favor of one without a widely understood folk meaning. The study of heredity is beset by such confusion, and the term heritability appears to be at the heart of some of the confusion. In this article, I discuss both the technical and folk meanings of heritability and examine the bridge between them. By continuing to use the term heritability, we risk promulgating serious misunderstanding about the workings of heredity, therefore I suggest selectability as an alternative term to avoid such pitfalls.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42804/1/10709_2005_Article_BF02259512.pd

Socioeconomic status and physical health, how are they related? An empirical study based on twins reared apart and twins reared together

This investigation used the powerful combined twin and adoption design to assess the validity of three different hypotheses--social causation, childhood experiences, and health selection--on the origin of the association between socioeconomic status (SES) and health. The sample contains 99 pairs of monozygotic twins reared apart, 166 pairs of monozygotic twins reared together, 238 pairs of dizygotic twins reared apart, and 221 pairs of dizygotic twins reared together, who completed questionnaire items concerning their SES and health status. Genetic effects, environmental effects unique to the individual, as well as environmental effects shared by twins were involved in mediating the associations between SES and health. However, the relative importance of these effects varied for the different associations depending on the measures of health and SES respectively. The results indicate that social causation, childhood experiences, and health selection may all be important for the association between SES and health. It is argued that these hypotheses are not contradictory, rather the relationship between the complex dimensions SES and health may be explained by several different causes.social causation health selection socioeconomic status health inequalities twins reared apart