In Nature, psychologist Paul Bloom has published a short rejoinder to 'social intuitionist' claims that rational deliberation has no role in shaping our moral convictions. His chief argument is that evolved emotional responses cannot explain how our moral sympathies change. A taste below the fold:
substantially and continues to do so. Contemporary readers of Nature,
for example, have different beliefs about the rights of women, racial
minorities and homosexuals compared with readers in the late 1800s, and
different intuitions about the morality of practices such as slavery,
child labour and the abuse of animals for public entertainment. Rational
deliberation and debate have played a large part in this development.
Emotional and non-rational processes are plainly relevant
to moral change. Indeed, one of the main drivers of moral change is
human contact. When we associate with other people and share common
goals, we extend to them our affection. Increases in travel and access
to information as well as political and economic interdependence mean
that we associate with many more people than our grandparents and even
our parents. As our social circle widens, so does our 'moral circle'.
But this 'contact hypothesis' explanation is limited. It
doesn't explain the shifts in opinions on issues such as slavery and
animal rights. Contact cannot explain the birth of new moral ideas, such
as the immorality of sexism or the value of democracy. It doesn't
account for how our moral attitudes can change towards those with whom
we never directly associate — for example, why some of us give money and
even blood to people with whom we have no contact and little in common.
There have been attempts to explain such long-distance charity through
mechanisms such as indirect reciprocity and sexual selection, which
suggest that individuals gain reproductive benefit from building a
reputation for being good or helpful. But this begs the question of why
such acts are now seen as good when they were not in the past.