April 14, 2010

Lisa DeBruine PhD
Department of Psychology
91 High Street
Aberdeen AB24 3EN, United Kingdom
01224 272218

Dear Dr. DeBruine:
SCIENCE made mention of your recent article published in the PROCEEDINGS OF THE ROYAL SOCIETY B. (When Macho Appeals ed. Constance Holder SCIENCE vol. 327 no. 5973 March 26, 2010 page 1561.)  I understand that you have evidence that women in countries where people are healthy, such as Belgium and Sweden, are relatively less attracted to very masculine looking men compared with countries like Brazil where health is less good and women prefer more masculine looking men.  The tradeoff suggested is that if health is generally poor women look for tougher looking men who might pass on an immune system that would help the children survive, but under healthy conditions women look for less tough men who might make more nurturing fathers.  This makes sense.

I am fascinated.  There are a couple of questions that come to mind.  The first is whether a masculine looking face is an honest advertisement.  Does a man who looks virile actually have a higher sperm count and greater reproductive success than a man who looks less virile?  If asked I would have said no, it’s just cosmetic.  But your article seems to me to imply that what you see is what you get; more virile looking men are more virile. 

The second question is whether facial features can be translated from one country to another.  Does a Swede who has the same degree of virility by appearance as a Brazilian also have the same sperm count and reproductive success? 

The reason this is important is this.  The world, Europe in particular, is going through a fertility crisis.  It has been decades since the developed world has produced enough children for long term survival.  The question as to why has to be the most pressing question of our time. 

I think I know why.  Confirmed by a number of independent sources, it appears that the fertility of a couple depends on the size of the gene pool they are in – their degree of kinship and that of their parents and ancestors.  In stark contrast with the usual superstition (if you define superstition as a belief held in defiance of evidence) fertility is greater the closer the kinship down to second cousins and closer.  Inbreeding depression is very rare.  The evidence I have been able to put together is on the internet at nobabies.net the March 25, 2010 entry. 

Although the evidence I have seems to me to be overwhelming, it is all indirect.  What I wish I could have would be averages of sperm counts from various countries and at regular intervals of time.  One could then watch sperm counts and birth rates decline together, if they in fact do.  Then it would be possible to follow sperm counts from generation to generation and watch them decline in populations in which outbreeding was the norm compared with populations that kept their gene pools tight and exclusive. 

I do not expect to see such data any time soon.  Not only would it be both embarrassing and impracticable to assemble a huge number of sperm samples for study, but “sperm count” is not a completely straightforward term.  One can count sperm, but the raw count is not everything.  Morphology and activity are also important.  That can probably be worked around in a smallish sample, say when calibrating facial appearance against sperm quantity and quality, but would become extremely difficult in a large study. 

Besides, it would be nice to look at this over a period of several generations.  There is no way to do a sperm count on my great grandfather (and I am pretty old myself) but his picture is available. 

So that is my biggest question.  Would it indeed be technically possible to establish virility trends over generations and between contrasting cultures by analyzing pictures of faces?

Another question arises.  It seems that if we as a species, certainly as a culture, are to survive, we must start marrying kin very soon.  Finding them would be quite difficult by using genomes, but it might be the best bet.  What about analyzing faces?

Please let me know what you think.


M. Linton Herbert MD 

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