Ethical issues in moral and social enhancement

3.4.2. Population perspective 
To see what aspects we would have to take into consideration in order to 
demonstrate the desirability of a population-wide intervention, let us consider an 
example. Assume that the reduction of anger in a given subpopulation might help in 
preventing negative consequences and make the subjects of the intervention behave 
in a way more conducive to moral outcomes – for example, by reducing the 
probability that they commit violent crime. One way, as Harris has proposed, is to 
promote better impulse control. If that cannot be done – because it is too costly, 
impossible or otherwise impractical – the second way is to weaken the underlying 
impulse. Changing the underlying impulse might be very difficult to achieve 
selectively, i.e. by targeting only those with a high propensity to feel anger, who at 
the same time are not able to selectively inhibit harmful displays of anger. If that 
claim turns out to be true, we have a 
prima facie
case for a population-based 
intervention. 
Both strategies (targeting high-risk individuals and whole population interventions) 
have their advantages and disadvantages (Manuel et al. 2006). In population-wide 
interventions, each individual usually only has a small expectation of benefit, and 
some will not benefit at all. This small benefit can be outweighed by a small risk. 
This happened in the World Health Organization clofibrate trial, where a 
cholesterol-lowering drug seems to have killed more than it saved, even though the 
fatal complication rate was only about 1/1000 per year (WHO, 1978). Such low 
risks, which can be vitally important to the balance of overall outcomes, may be 
hard or impossible to detect. If our rationale for the intervention is to reduce violent 
crime and deaths caused by violent crime, it would be a Pyrrhic victory if more 
people died and suffered lower a quality of life then were saved, or otherwise 
benefited, as a result of the intervention. Analogically, it would be a Pyrrhic victory 
if the improvement in the behaviour of some was more than offset by a decrease in 
11
I am grateful to Soren Holm for that point 

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morally desirable behaviours in others. We do not propose indiscriminately 
lowering populations’ sex drive only because there are some sex offenders. In that 
case we can even put the issue of liberty aside; we do not propose it because the 
calculation of the loss of utility to many is simply not worth the prospective and 
speculative gains.
So to be able to argue for a population-wide intervention that would result in the 
individuals in the population being, overall, morally better, we have to show several 
things. We have to show that the modification is indeed a modification in our moral 
sphere – the assertion that a proposed modification is pro-social is not enough. 
Moreover, we should demonstrate a reasonable expectation of efficiency – cost-
effectiveness as compared to alternative interventions – and show that the side 
effects are unlikely to have consequences overweighing the benefits brought by the 
intervention. Our overall assessment would also include the effects of the 
modification of traits on peoples’ moral lives in general. Again, this kind of 
argument can conceivably be made, but it has to be informed by moral theory. 
Unfortunately for many of the commentators, ‘more empathy’ or ‘less anger’ is 
simply not enough.