April 12, 2010

Robert Michael Ph.D.
The HarrisSchool
1155 East 60th Street
Chicago, IL 60637
Phone: 773-702-8400
E-mail: HarrisSchool@uchicago.edu

Dear Dr. Michael:
I appreciated your contribution to the documentary “Demographic Winter.”  One point you make is that basically monogamy makes people happy.  That is good news since we would like people to be happy and would like people to be monogamous; it’s good for the children.  It is good to know that the goals are not in conflict. 

Another point is that the poor and disadvantaged tend to have children who will be poor and disadvantaged.  That is the kind of problem that invites people to throw money at it.  But there is a deeper cause.  I know of no good study showing that the poor and disadvantaged in this country are the ones having the children nor do I know of anybody who doubts it.  Certainly the global statistics bear it out.  The poor and disadvantaged countries have the higher birth rates. 

This is something about which people have shrugged, wondered and occasionally taken ill advised action.  It is regarded as one of life’s imponderables, unexplained and paradoxical.  But there is a perfectly simple explanation that people really ought to know about and policy makers should bear in mind.  You will doubt this at first because it is not what everybody else has always told you.  So grit your teeth and prepare to look at evidence you do not expect to see coming from impeccable scientific sources.

The fact is that fertility depends with exquisite sensitivity on the kinship of the couple and of their parents and so forth.  I do not have iron clad evidence that this effect is manifest in the first generation, but it is clear that it accumulates over multiple generations.  So far I trust that is not a surprise.  What may be a surprise is that for practical purposes the closer kin people are the more fertile they and their children will be.  This is the opposite of what I am sure you have repeatedly been told.  But this time there is evidence.

Rather than burdening this letter to a discouraging degree with the proof, let me direct you to a poster I presented at a genetics convention last month.  It is at NoBabies.net, the March 15, 2010 entry.  You will find professional studies published in prestige peer reviewed articles that show animal studies relating population size with fertility; environmental pressure plays little role.  It’s all population size.  You will find two studies in humans that show the same thing the animal studies show.  You will find two studies in humans of essentially isolated populations of humans and how the community size evolves over time.  You will find a number of historical studies that show the impact this has had on history.  Rare is the regime that breaks the three hundred year brick wall.  And you will find an analysis of the world’s birth rate, with which I am sure you are all too familiar, that demonstrates that we are all following the same dynamic course and are headed toward the fate of other isolated communities.  Yes, the earth is quite isolated. 

Have a look at it and please let me know what you think.


M. Linton Herbert MD

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