Genetics and Human Behaviour: The Ethical Context
Determinism and fatalism
12.10 One common ground for the view that genetics undermines responsibility for oneself is the claim that genetics is a deterministic theory. This claim can be interpreted in many ways, but in the present context it can be taken as the hypothesis that the laws of genetics show that an individual’s genotype determines an important range of facts concerning his or her life, including facts about a range of fundamental human abilities and dispositions.
12.11 In thinking about this position, it is useful to start from a thesis often associated with deterministic conceptions of human life, namely, fatalism. Fatalism is the thesis that that which is determined is ‘fated’: in other words, that it will take place whatever one chooses or attempts to do. Traditionally, fatalism was associated with myths concerning the power of gods over human life.(6) These myths are no longer believed, but fatalist language is still used to describe inescapable aspects of life, as when one says that everyone is ‘fated’ to die. In a similar way, fatalist language can be used to express the view that genetic discoveries imply that significant aspects of life are inescapably fixed by the identity of one’s genes: as James Watson has put it, ‘our fate is in our genes’.(7)
12.12 A distinct thesis is that of determinism, which, in this context, is the view that what we choose to do is determined by factors outside our control. Non-fatalist determinists allow that an individual’s choice makes a difference to the course of his or her life, but hold that his choice has itself been determined. This is different from the fatalist thesis because it means that our choices do play a causal role, whereas the fatalist believes that future events will take place regardless of what we choose. Nonetheless, many determinists are also fatalists. This combination is particularly relevant here since, fatalism is clearly incompatible with the conception of ourselves as responsible moral agents.
12.13 If it were true that genes have inescapable implications concerning the later course of life, this fatalist language would be appropriate. But it is far from evident that these implications really are inescapable. In the case of some diseases, this is, in fact, the case. For example, those with the mutant allele responsible for Huntington’s disease are indeed fated to develop this condition, although this is fortunately a rare condition. In the case of most diseases, however, genetic mutations lead only to a predisposition, or risk, of developing a condition. Moreover, there are generally also courses of action (such as a change of diet or lifestyle) which those diagnosed as being at risk can pursue in order to lessen the chance of their actually developing the condition in question. So these cases, which are overwhelmingly the most common, are not cases in which talk of fatalism is appropriate. Phenylketonuria (PKU) is a good case in point. This is caused by a recessive allele of the PAH gene(8) on chromosome 12 and is associated with serious mental retardation. It turns out that this association depends on following a normal diet. Once someone identified (soon after birth, through a blood test) as carrying the two recessive alleles adopts a diet low in the amino acid phenylalanine, this association is broken and the person concerned can develop relatively normally.
12.14 It is, then, plain that understanding the effects of our genes in the case of disease does not lead us to fatalism. In the case of behaviour, the reviews of the evidence in Chapters 7–10 demonstrate that in so far as there are genetic influences on behaviour, these do not follow the very rare pattern exemplified by Huntington’s disease. Instead these genetic influences involve predispositions to aggression, anxiety, low or high intelligence and so on. They do not imply that the chances of these predispositions being realised are unalterable. On the contrary, when the outcome is undesirable, their discovery provides an incentive for intervening to enable those with the predispositions to learn how to control and overcome them. Equally, when the outcome is desirable, those found to have the relevant predisposition may be motivated to make the most of their genetically given qualities.
12.15 Thus, the effect of one’s genes is not to fix the future structure of life as a fate from which one cannot escape. Equally, the effect is not to fix the structure of one’s character, the kind of person one is. Genes certainly contribute to the initial make-up of one’s abilities and motivations. But it does not follow that one cannot do things which develop these abilities and alter one’s motivations.
Footnotes6 For example, according to Greek myth, Apollo decreed that Oepidus, the son of Laius, would kill his father and marry his mother. Even though Laius, when told of this decree, attempted to avert his fate by arranging to have Oedipus killed as an infant, the myth recounts that Oedipus’ life was saved and that he went on, unknowingly, to fulfil Apollo’s decree.
7 Jaroff, L. (1989). The Gene Hunt. Time Magazine March 20.
8 Phenylalaninehydroxylase (PAH) gene.