On the Heritability of Jazzophilia

Abstract

If learning has a lot to do with complex behavior but nothing to do with real cognitive growth, we then must ask ourselves what is the purpose of our attempts, often with a great expenditure of time and money, to determine the quantitative extent of so-called heritability of various kinds of behavior. Heritable is that part of behavior that is supposedly genetically fixed and therefore transmitted to the offspring. What remains of the very same behavior is then consequently ascribed to the determining influence of the environment so that, in the most simple cases purely in an additive manner, the sum of the two factors decides the actual expression of a type of behavior. In many cases, it has been shown that the kind of interaction between the genome itself and the environment can influence the form of a type of behavior. Nevertheless, in all these cases, we start out from the concept that in principle it is possible to differentiate between these two forms of an instruction to the organism. The intrinsic scientific purpose of this division is that a biological theory of behavior must be particularly interested in the genetically mediated part since this alone is of significance for evolution. Everything else caused by various environmental influences and partly by purely coincidental factors is devoid of any such special significance since the empirical refutation of Lamarck’s ideas is an established fact and that there can be no inheritance of acquired characters. The efforts of the biologists to peel away the, for them, all-important evolutionary part from all the observable characters is therefore easily understood and should, therefore, be viewed without any of the many supposed implications for an eventual moral judgment of human behavior. The strong need to pass the latter has produced some odd quirks in the field of experimental psychology and this is no coincidence. The perennial debate over nature versus nurture is so overburdened with ideology that no attempt should be made here to describe the all too well-known details (cf. the “sociobiology-battle” described very vividly in Segerstrale 2000). What is of much greater interest within the framework of an evolutionary theory of cognition must be related to the basic methodological justification of such a determination of heritability. Should this turn out to be criticizable or even refutable regarding its axioms, it would have inevitable consequences for what has been the customary splitting up into nature and nurture and the polemic that has been associated with it in the open debate.

The old problem of the relation between heredity and environment in evolution ... has, I think, largely been cleared up by the recognition that the capacity of an organism to respond to environmental stresses during development is itself a hereditary quality.

C. H. Waddington

We will find the individual genes, even those for complex character traits which are affected by several genes.

Robert Plomin