[ExI] The Catholic Impact (was Re: Origin of ethics and morals)

[Kelly Anderson]

On Tue, Dec 13, 2011 at 4:24 AM, Anders Sandberg <anders at aleph.se> wrote:
> Hmm, what was the selection pressure from priestly celibacy? One source I
> glanced at suggested a density of 0.25% clergy, or one in 40. Assume that
> you need above intelligence to join the clergy: this means that the fitness
> of the smarter people will be 1-(1/40) (assuming they could keep it in their
> cassocks, which was not always true).

Ya, made that point... :-) Let's just neglect it for the moment...

> Now, intelligence is due to a lot of small gene components with overall
> heritability h^2=0.5 or so. In selection experiments h^2=(R-M)/(S-M), where
> R is the response in the population trait, S is the value it had in the
> selected parent population and M is the population mean. As parents for the
> next generation we have a population with mean intelligence S = 0.5*(100-12)
> + 0.5*(100+12)*(1-1/40) = 98.6 (the first term is the under iq 100 people,
> the second the slightly decreased 100+ population, and 12 is the expectation
> of a half normal distribution). So we should expect an IQ in the next
> generation of (98.6-100)*0.5 + 100 = 99.3. Not much.

Trying to follow along here... where does the 12 come from? Is that
the presumed difference in IQ between the priestly class and the
normal class?

> OK, lets make a recursion out of this. Let M(t) be the population mean
> smarts at time t, and assume it is always the upper half that has a chance
> of becoming clergy and that variances stay the same. S(t) = 0.5*(M(t)-12) +
> 0.5*(M(t)+12)(1-1/40) = [(1-1/80)M(t) -3/20].
>
> M(t+1) = M(t) + h^2 (S(t)-M(t)) = (1 + h^2 (1-1/80) -h^2)M(t) -h^2 3/20 =
> 0.99375 M(t) - 0.075.
>
> Not the nicest formula, and I might have slipped somewhere. But running this
> from M=100 at  the First Lateran Council (1123) to the present (36
> generations) produces an overall reduction of population IQ to 77.37. The
> present IQ of Italy is 102, so I suspect this overestimates the continence
> of priests, the selection effect, heritability and entry requirements to
> clergy.

Great stab at the math!!! Reality is clearly a little different than
this... there must be a lot of other things going on... at least in
Italy.

-Kelly