kim@emory.UUCP (06/14/84)
This should be in net.bio, but since it keeps coming up in this newsgroup I feel I need to comment. There seems to be a basic lack of biological understanding when discussing the issue of genetic determinism. At the risk of being repetitive let me point out some fundemental concepts. First all genetic traits are expressed as the result of an interaction with an environment. What is produced from this interaction is a PHENOTYPIC trait. This is the observable expression of a gene X environment interaction. For some phenotypic traits the amount of variance produced in different environments is small so we say that the degree of genetic influence is great (eye color, hair color), whereas for other traits the variance between environments is great so we say that the genetic influence is small (IQ, preference for chocolate ice cream). However, even the most easily influenced trait has a genetic component if only the physical structure that allows the enviornment to act on the individual. Similarly, the most strongly genetically influenced trait requires a nurturing environment for its expression. To ask which determines the expression of a trait when its expression is dependent upon both genetics and environment is like asking whether a car travels accurately down the highway because of the driver or the engine. Take either one away and it stops going anywhere accurately. We can say the engine may be more important for motion and the driver for accuracy, but it is pointless to argue which is more important. To make this relevent to a discussion of humans one needs to be clear what they want to do with the infomation obtained. If the goal is change than knowing the environmental lability of a trait can tell you what might be the best approach to produce change. Knowing something about the stability of eye color in most environments would lead me not to advocate changes in socialization as a way of altering eye color. Knowing something about the lability of IQ would probably lead me to advocate different educational techniques to increase it. This doesn't mean there is no genetic component to IQ, just that genetics contributes a small, but measurable influence on IQ. Change is better achieved by trying to alter the environment that altering the genotype. Kim Wallen Psychology Dept. Emory University Atlanta, GA 30322 akgua!emory!kim