Born to run (slowly) and to loaf-The Leiberman hypothesis?

Harvard Professor David E. Leiberman  has taken Theodosius Dobzhansky's maxim to heart; "Nothing in biology makes sense except in the light of evolution."

Leiberman,also known as the barefoot professor for his interest and advocacy of barefoot running ,expounded his thesis along with co author Dennis Bramble in a 2004 article in Nature entitled " Endurance running and the evolution of the genus homo."

Quoting from the above article ;" The fossil evidence of these features [features that facilitate endurance running] suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years and may have been instrumental in the evolution of he human body form."


Leiberman's theory suggests that Homo evolved the ability to run long distances and hunt and forage in the heat before the human brain grew and humans got smart enough to  rule the roost .

The creature than evolved  could be described as a fur less,short toed,sweaty bipedal endurance athlete who was typically at the edge of negative calorie balance and who tended to loaf and rest whenever he could to conserve energy as food was scarce and difficult to obtain.These were the hunter gatherers whose survival depended on their ability to track and hunt animals over long distances in the climates of the African savannas as well as to dig around and find what they could to eat. That stylized story is that is how our ancestors lived as recently as some 600 generations ago, according to some estimates.

As the pressing need to work very hard physically became less and less necessary for more and more people the evolved human's drive to rest and conserve energy persisted and when not countered by lots of exercise obesity and the modern maladies such as  arterial diseases and type 2 diabetes went from rare to increasingly common.

It is an appealing story,one that resonates with those among us who like to do endurance type exercise. This includes Leiberman .  Much of it seems to make sense and is rich in physiologic insights, but is it all  just an "as if story"?

Hans Vaihinger is known as the philosopher of "as if". His view was that one should not ask if a theory or belief was true in some deep probably unknowable objective sense but rather is it useful to act as if the theory were true. ( I think Milton Freidman spoke of economic models or theory in that way, that is are they useful.) From reading descriptions of Vaihinger's work, I think it seems to him maybe most stories are "as if stories". George Box is quoted as saying that all models are wrong but some are useful.

Leiberman writes and speaks well in an entertaining way and regales us with mechanisms  such why tighter ( rather than more lax) Achilles tendon enables running and why longer toes are a detriment to running  and how sweating works much better as a heat dissipation mechanism than panting.

Bob Wachter's defense of ABIM's shenanigans and Mel Brooks

Dr. Bob Wachter,former chair of the ABIM, has spoken out in defense of ABIM and , of course, of himself.

Several medical bloggers have offered their critique of his comments including Michel Accad,  ,Walter Bond. and Dr RW..In my opinion all make  some good points with which I agree.

But I think Med Brooks' comments  may be the most appropriate.

Can Dr. Cassel and her collaborators at the National Quality Forum repeal Goodhart's Law?

In the December 4, 2014 issue of the NEJM, Dr. Chistine K.Cassel et al expound on performance measures.She freely admits there have been some problems but also apparently some successes.It is just a matter of learning from the mistakes and  leveraging the successes. We just have to work harder and be smarter. "Getting More Performance from Performance Measurements" Cassel, CK et al , NEJM 371,23 2014). When people talk about "leveraging" you can be sure the tripe level is dangerous high.

She offers her explanation of  why the notorious "four hour pneumonia rule" did not work out well. That particular clinical situation was "not the right place to intervene". .."There was too much clinical variability for the measure to help physicians on exactly the right course of action." True enough but that was not the reason.

The underlying insight is found in Goodhart's Law which states that when a measure becomes a target it loses its value as a measure.A more basic insight is that people respond to incentives. When folks are graded, or rewarded or punished based on some measure they will find ways to achieve that target and if better care results fine but there is not reason to think apriori  that it will. Teachers will teach to the tests and students will study for the test regardless of how well or how badly the test reflects the students' mastery of the subject.


Goodhart wrote about his "law " in 1975 and in 1976 Donald Campbell wrote in regard to education and testing :

"achievement tests may well be valuable indicators of general school achievement under conditions of normal teaching aimed at general competence. But when test scores become the goal of the teaching process, they both lose their value as indicators of educational status and distort the educational process in undesirable ways.

It is tempting to substitute medical care for  the teaching process and we get "But when quality measures become the goal of the medical care process , they both loose their value as indicators of medical care and distort the process in undesirable ways."

I submit that devising better measures will not change the situation.

Dr. Cassel et al would disagree with my view and she closes her commentary with  the usual boiler plate words about "stakeholders"  and better quality down the road. "All stakeholder groups are now invested in getting more  performance out of measurements ,which should ultimately drive the care improvements that patients need and deserve."

 The economist,Arnold Kling, give his take on performance measures or P4P  here.

I have commented on this general subject before and here  the issue of a conflict between P4P and traditional medical ethics is talked about.

The folks at the National Quality Forum can no more negate Goodhart's law than they can make it now longer the case that people respond to incentives.The stakeholders of which Cassel speaks , of course, included the NQF itself as it is in the business of writing quality standards .