> 1) The stylised demographic facts appear to be that the birth rate falls
> as populations become wealthier, that this fall in the birth rate is due in
> significant measure to an increase in the number of childless households,
> and that within populations in both the developed and developing worlds,
> the incidence of childless households increases the further up the income
> distribution you go.
>
Though I don't have the figures I would guess that true 'childless households' are very rare. Most childless households eventually end up with a child or two. It's a mistake to look at couples who have refrained from having children for a comparatively long time as never going to have them.
Of course delay in breeding lowers the rate of population growth - as Dawkins himself once said, "Population banners that read 'Stop at two' might just as well read 'Start at [age] thirty'"
> 2) Is this not a very severe problem for most sociobiological theories, or
> for any theories which rely on "the desire to propagate genes" as being a
> major determinant of human behaviour? At the very least, it is an anomaly
> to be explained away, that those members of society who might be thought to
> be best placed to have large families, tend not to.
>
> The best the Dawkinsites I've spoken to seem to be able to come up with
> seems to be just-so stories about the management of large and small prides
> of man-cubs on the plains of Africa. But I don't see how this can explain
> the decision to have no family at all.
>
Again, comparatively very few people in a position to mate forgo having
children entirely. However, it is wrong to view individuals that do not
breed as making no contribution to the perpetuation of the genes they
carry. You do not need to perpetuate genes through your children - you
share on average the same percentage of genes with your children as you
do with your siblings, so if you do not breed yourself but nonetheless
contribute to the survival of the children of your brothers or sisters,
you have 'perpetuated your genes' (I don't like this kind of language
but use it because it is widely known, if also widely misunderstood). In
terms of shared genes your niece is worth as much as your grandchild.
It's worth remembering that maximizing the number of children you have isn't necessarily the best way to 'spread your genes' (it is probably better to think of maximizing the number of grandchildren you have ...) This is the basic reason why the demographic shift doesn't have to contradict standard Neo-Darwinian reasoning.
Incidentally why does it seem that leftists are so hostile to Dawkins?
>From what I've read by him a) pretty much everything he says about
evolution seems perfect sense and ought to be uncontroversial if
understood properly, and b) NOTHING HE SAYS IN ANY WAY (necessarily)
INDICTS A LEFT OR SOCIALIST PROGRAM.
So what's up?