July 5, 2011
letter to be posted on nobabies.net
Florian Lederbogen
Central Institute of Mental Health
University of Heidelberg Medical Faculty
Manheim 68159
Manheim
GERMANY
florian.lederbogen@zi-mannheim.de
Dear Florian Lederbogen:
I read with delight your work on the neuro circuitry of anxiety produced by urban living and urban upbringing. (City Living and Urban Upbringing affect neural social Stress processing in humans, F. Lederbogen et al. NATURE vol. 474 no. 7352 June 23, 2011 page 498 and glowing comments A New York State of Mind ECONOMIST vol. 399 June 25, 2011 page 94 also Allison Abbott City Living Marks the Brain NATURE page 429 and Daniel P. Kennedy & Ralph Adolphs Stress and the City NATURE page 452) There is a control that begs to be run and I am hoping that you will do so.
You point out that people living in cities have a higher incidence of anxiety and schizophrenia and then put the issue to the test, exposing subjects to conditions that nicely portray the exasperation of daily life and showing how their brain circuitry responds and showing differences that correlate with urban living.
Of course anxiety can ruin your day, but heedless folly is likely to kill you a lot faster. There are other issues that follow the same logic. Starvation kills faster than obesity. Shock kills before hypertension. Hypoglycemia kills before diabetes. Since anxiety, obesity, hypertension and diabetes seem to be increasing together, one might speculate that they are all disorders of fine-tuning. Nature has greater defenses against the more lethal threat and if there is an imbalance the direction is determined by the evolutionary equivalent of prudence. Perhaps schizophrenia, also a more urban plague, is also a matter of fine tuning, but I cannot imagine what its opposite might be.
But fine tuning of what? Your excellent work provides the first possible example I know of. The response of the amygdala in the brain seems to be an effect of current urban living, to be environmental, and it seems to me needs no further apology. But the tuning between amygdala and perigenual cingulated cortex seems also to be affected by urban upbringing.
That observation starts klaxons in my mind. I would suggest that people who grow up in the country are offspring of families that have lived in the country. That does not seem to be a daring guess. Nor is it daring to suggest that as far as evolution is concerned your current state of tranquility is a lot less important than the number of grandchildren you have.
Now the important bit: The number of grandchildren you are likely to have depends very strongly on the degree of kinship you have with your wife, this being true to the point of surprisingly close kinship. This was clearly shown to be true in humans by examining the Icelandic genealogy. (A. Helgason et al., Science 319 813 (2008)) The moral seems evident: marry kin or suffer a severe reproductive handicap in this generation and the next. In fact there is evidence that the handicap accumulates over a number of generations and ends in catastrophe, but that is beyond my current scope.
If ignoring kinship ties when selecting a mate can produce so evolutionary profound an effect as infertility, it seems reasonable to wonder whether it can also affect how we feel.
I hope that German genealogy records, while not as exhaustive as the Icelandic records, are sufficient to establish degrees of consanguinity at least to a certain extent following the same logic. I would assume that those from rural families have greater consanguinity. Thus rural upbringing must correlate both with better ability to tolerate stress and with consanguinity of the parents and in all probability at least to a certain extent consanguinity of the parents must correlate with better stress tolerance.
That alone would not prove much. It could still all be environmental. Still one does not know what the numbers are going to be until one looks. It might well prove that consanguinity of the parents is such a good predictor of the effect you have demonstrated that you will turn the whole field on its ear.
Of course that means the full wrath of the establishment will come down on you such that you will be ignored, vilified, ridiculed and so forth. But that’s what you get for trying to do something important, is it not?
There is more data on my web log and of course I am at your disposal if you would like more information laid out for you or for any other reason.
Sincerely,
M. Linton Herbert MD
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