Monday, November 30, 2009

Exercise and Arthritis

For the past two weeks I have been working on a lengthy post about the risks associated with exercise (with the goal being to help us think more rationally and consistently about our attitudes towards different kinds of preventative medicine). So when I noticed this study this morning I wanted to link to it here.

Expect my substantive post on exercise in the next few days.


Sunday, November 22, 2009

Main Menu (Nov. 2009)

Thursday, November 19, 2009

Egalitarianism and Ideal/Non-Ideal Theory

Suppose one considers oneself an "egalitarian". And by that I mean one who believes in distributive equality (rather than moral or political equality). And this egalitarian also has philosophical inclinations, and thus they wish to undertake the project of developing an egalitarian theory of distributive justice.

And, for the purpose of the exercise today, let us also suppose further that our egalitarian philosopher is primarily interested in developing an egalitarian theory of domestic justice for an affluent, liberal democracy like the US, Canada or England (rather than a global egalitarian theory of justice that encompasses all people in the world).

How does one go about developing such a theory? Where should one start?

One might start at the level of “ideal theory”. That is, one could begin by pondering what they think the ideal society would look like (i.e. one where everyone is equal!), and then derive some egalitarian prescriptions from that exercise (i.e. inequalities shouldn’t be tolerated).

Alternatively, one could start at the level of “non-ideal theory”. In other words, one could begin by pondering what actually causes different kinds of inequality in the real world and what has, and what might prove to be, effective ways of fairly and efficiently mitigating such inequalities.

A significant bulk of the ink spilled in political philosophy over the past few decades has taken up the first project. And a central impetus for this has been John Rawls’s theory of distributive justice, in particular Rawls’s famous difference principle- which permits socio-economic inequalities provided they are arranged to the greatest benefit of the least advantaged.

Two of the most prominent debates egalitarian philosophers have had of late concern the questions (1) Equality of What? (resources, welfare, opportunities for welfare, capabilities, etc.?), and (2) what is the scope of egalitarian principles (e.g. do they only apply to institutions, or do they also apply to the individual decisions we make in daily life?).

The latter issue receives extensive treatment in Cohen’s latest book and has now come to dominate the attention of egalitarian political philosophers. In particular, a great deal of attention has, and continues to, be paid to the concern of whether it is unjust for self-seeking highfliers to threaten to withhold their productive talents unless they receive very high incomes, incomes that promote socio-economic inequality.

An outsider who first happens upon this literature could easily form the impression that egalitarians are so concerned about the employment decisions of highfliers *because* these decisions are the major cause of inequality in real societies. That might be a natural assumption to make, but it would be mistaken.

The main reason why egalitarian philosophers spend so much time concerned about these issues stems from the fact that John Rawls wrote this book back in 1971. And in this book, Rawls developed what is called the “Pareto argument” for inequality. Rawls argued that a deviation from equality is justified so long as everyone benefits from it.

And how could a movement away from equality benefit everyone? Enter the issue of incentives. By offering the promise of a higher post-tax income to the most talented members of society we can entice them to be more productive than they would otherwise be. If their higher level of productivity brings benefits to everyone then there is no reason to insist on the initial equal division. The underlying intuition behind egalitarianism is, for Rawls, a concern for the least advantaged in society. Why object to a movement away from equality if everyone, including the least advantaged, benefit? Rawls believes that there is no reasonable reply to this question. The difference principle combines considerations of equality with those of efficiency.

The question that has always come to my mind as I read over the egalitarian literature on these debates in the past decade is this—is it true that incentives are the real cause of the inequalities that exist today? For if they aren’t (which seems to me to be the case) it is rather odd to fixate so much on the incentives issue.

But the ideal theorist can respond to my point in the following way— "but we are not (at least primarily) concerned with the real world. We are concerned with what kind of behaviour would be permissible in the ideal world. And in the ideal world, we egalitarians disagree with Rawls that the talented members of society could justly withhold their talents unless offered inequality-generating incentives".

There are many things to say in response to this reply. Firstly, why think that the kind of talented highfliers Rawls posits in the Pareto Argument would even exist in the “ideal world”? Assuming, as I think is clearly the case, that in the egalitarian society all would have access to a decent education, etc., why think that super-talented individuals who could single-handedly create a more optimal cooperative surplus if offered the right kind of financial incentive, would even exist? (in fact, I am sceptical such people exist in the real world!) That is just one of many things that has troubled me about having the debate at the level of ideal theory. It mixes real-world concerns (like Cohen’s concern that Thatcher’s tax cut could be justified by reference to these incentives) with abstract, idealized scenarios where supposedly real-world facts have no relevance or place.

If real-world facts have no relevance or place in ideal theory, then why fixate on incentives rather than some other behaviour that could possibly perpetuate inequality in the ideal society? I can't think of any examples off the top of my head, perhaps because I am sufficiently deficient in my capacity for idealization, but I'm sure the ideal theorist could come up with some. Maybe the most talented highfliers will also demand to couple and reproduce with the most talented partners, thus perpetuating genetic and social inequalities by commanding the highest family incomes and passing on the "superior" and "selfish" genetic endowments that constitute these self-seeking highfliers. Maybe if Rawls invoked that example it would have been debated for 20 years. But I'd like to think not. Deep down I think egalitarians are drawn to the incentive case because it tracks what they see as a relevant and true empirical reality-- that people often respond to incentives.

Rather than starting one’s quest for an egalitarian theory of justice with the remnants of an academic debate about a book published over 40 years ago, I would encourage the next generation of egalitarians to start at the level of non-ideal theory. This would involve, as I outlined here, developing 3 different skills.

1. Ascertaining how we got to where we are and understanding why things are this way.
2. Deliberating about the kind of world we want to have.
3. Judging how far, and through what actions, and at what risk, we can realistically hope to move this world as it now stands towards the way we might excusably wish it to be. (Dunn, 1990, p. 193)

Rather than invest the bulk of one’s energies sifting through 30 some odd years of Rawlsian scholarship, the next generation of egalitarian philosophers should begin by asking “Why is there inequality?”. So this recent paper, for example, should serve as the starting place for serious egalitarians. This study concludes that “differences in the technology by which a people derive their livelihood and in the institutions and norms making up the economic system jointly contribute to this pattern [of inequality]”. This is good news for Rawlsians, in that the basic structure is indeed important. So Rawls was on the right track when he claimed that the basic structure is the primary subject of justice.

But, as I noted before, egalitarians (and Rawlsians) also need to appreciate how complex the factors that lead to inequality are. This study found that health inequality among infants in the US actually declined. However, the reasons for this include the fact that highly educated parents are more likely to utilise fertility treatments, which increase the chances of multiple births. So the narrowing of the gap was achieved, in part, by a leveling down. Rather than have the children of affluent parent’s suffer higher risks of infant mortality (which makes things more “equal”), the goal ought to be bring all up, to minimize the risk of infant mortality. Or recall my earlier post here, which addressed the concern that the behaviour of some educational elites (when it comes to choice of partners) perpetuates inequality.

Anyways, taking (1) seriously shows us that institutions *and* individual behaviour matter in terms of the complex factors that influence different kinds of inequality.

What about (2)—what is the ideal? Unfortunately most egalitarians jump straight to this. And the ideal is-- we should be *equal* in something (e.g. welfare, wealth, capabilities, etc.).

But once one takes the empirical constraints of (1) and (2) seriously, I believe one’s account of (2) would become more attractive, defensible, feasible and (most importantly) *provisional*. One can get a better sense of “what” should be equalized. Indeed, one might even temper their egalitarian ambitious and opt instead for a principle of sufficiency or priority. Indeed, this is what has happened to me.

And skill (3) is where the real action is. “What Needs to be Done?” should be the overarching concern of the egalitarian. How do we move from our unequal situation to a more just one? Unfortunately, egalitarians tend not to think much further than “take money from X (the rich) and give it to Y (the poor), thus creating more equality!”.

But appreciating the complex factors highlighted by (1) will, I believe, expand the imaginative capacities of egalitarians, providing them with a better sense of what would constitute a feasible timescale for achieving their egalitarian aspirations (given our history and circumstances) as well as a better understanding of the things that can help them realise a better world (like public health measures, such as sanitation, vaccinations, etc.). And so science would come to the fore, and egalitarians would engage in new questions concerning the role of innovation in a just society, and how to ensure the benefits of technology and medicine are efficiently and fairly dispersed.

One last point. In exercising skill (1) the egalitarian should also ask why it is that they themselves are egalitarians (or rather why they have egalitarian intuitions; I have yet to meet a self-described "egalitarian" who actually lives like an egalitarian!).

Now Cohen himself provides some autobiographical details, like his upbringing here. But I don't mean we should just ask what the proximate cause of our moral sensibilities are. I mean we should ask why we, as a species, have the moral sensibilities we have (so what are the ultimate or evolutionary causes? And this in fact links up with Cohen's point about the influence of religion in his life, so there is an important link there). And one of these sensibilities, which seems to be more prevalent in some more than others, are the egalitarian sensibilities that our egalitarian philosopher starts off with. I won't go into this topic here today, but I believe that, once the theorist critically reflects on their own starting intuitions, then it will profoundly influence the way they go about developing and assessing a theory of distributive justice. But that is an expansive topic for another day.


Wednesday, November 18, 2009

PNAS Study on Telomere Length and Centenarians

Why is it that some people, who are exceptional cases, can live 100 years of disease-free life while the vast majority of their contemporaries die from cancer, heart disease or stroke 20-30 years earlier?

This is perhaps the most important question which the medical sciences should be tackling today, rather than the questions which currently dominant the "disease model" approach to health extension (e.g. what causes specific diseases, like cancer, stroke, AD, etc.).

If we had a better understanding of the things that influence "healthy aging" then we could reduce the increasing risks of morbidity and mortality which aging populations face.

Contrary to what most people might be inclined to think, exercise alone will not make the goal of a century of healthy life a reality for the vast majority of people alive today. If we are to increase the average life expectancy beyond 85 years, and do so in a way that "adds life to years, not simply years to life", we will need to find a way of modulating the aging process.

Studies like this one, published on the "Early View" of the Proceedings of the National Academy of Sciences, are where the real action is in terms of the new frontiers of the medical sciences. Here is the abstract:

Telomere length in humans is emerging as a biomarker of aging because its shortening is associated with aging-related diseases and early mortality. However, genetic mechanisms responsible for these associations are not known. Here, in a cohort of Ashkenazi Jewish centenarians, their offspring, and offspring-matched controls, we studied the inheritance and maintenance of telomere length and variations in two major genes associated with telomerase enzyme activity, hTERT and hTERC. We demonstrated that centenarians and their offspring maintain longer telomeres compared with controls with advancing age and that longer telomeres are associated with protection from age-related diseases, better cognitive function, and lipid profiles of healthy aging. Sequence analysis of hTERT and hTERC showed overrepresentation of synonymous and intronic mutations among centenarians relative to controls. Moreover, we identified a common hTERT haplotype that is associated with both exceptional longevity and longer telomere length. Thus, variations in human telomerase gene that are associated with better maintenance of telomere length may confer healthy aging and exceptional longevity in humans.

And an excerpt from the article:

In summary, we provide strong correlative evidence that individuals in Ashkenazi Jewish families with exceptional longevity have better maintenance of telomere length and that the telomerase genes may function as important genetic determinants of both human longevity and telomere length. Additionally, our data suggest that both telomere length and variants of telomerase genes may have a cumulative influence on lower disease prevalence and a favorable lipid profile in centenarians and their offspring. Additional comprehensive studies on genetic and genomic variation of centenarians and their offspring comprising candidate genes, especially those known to play a role in telomere maintenance in model organisms, may reveal previously undescribed genomic regions and molecules that are operative in human health and longevity.


Friday, November 13, 2009

David vs Goliath

The story of humanity is a fascinating and inspiring one.

Despite the great adversity our species has, and continues to, face, we are capable of great compassion, imagination and inspiration. Indeed, it is perhaps these human traits that have helped us overcome the almost insurmountable obstacles we have faced in our species' evolutionary history.

What we are today reflects the challenges we have had to overcome in the past. From our two eyes and two hands, to our emotions like love, hope and fear, we are a complex history of biological and, more recently, cultural evolution. The inhospitable and unpredictable environments in which our species lived has given us aggression and compassion, emotion and reason, fear and happiness.

To help us overcome starvation we developed tools for hunting and farming. To help us overcome infectious disease we created the sanitation revolution and vaccinations. Our ability overcome diverse and complex forms of adversity is admirable.

The history of humanity is thus one of struggle (with all of its accompanying tragedy) but also one of hope (with all of its accompanying inspiration). Hope for a better state of affairs. One where humans have more opportunities to enjoy health, love and happiness. This aspiration to make things better is, I believe, what makes us truly human. And it is an aspiration that links us to our distant ancestors.

The title of this post is "David vs Goliath". Humanity is David, and Goliath represents all the things that have, and continue to, challenge the health and welfare of humans. The specific form of Goliath alters over time. Reflecting on the causes of death in the 20th Century, for example, we see that Goliath was warfare (including two World Wars), totalitarianism, and, most importantly, infectious disease. The Flu pandemic of 1918, for example, killed an estimated 50 000 000 people, which is more than 3 times the estimated number of deaths caused by four years of “Great War” in 1914-18. And small pox is estimated to have killed between 300 and 500 million people in just the 20th century.

In the 21st century, Goliath is CHRONIC DISEASE (e.g. cancer, heart disease, stroke, etc.). Just 1 year of chronic disease today kills as many people as 300 years of the Black Plague.

In the decade from 2005 and 2015, the World Health Organization estimates that 220 million people will die from chronic illness, 144 million of these deaths will be in lower middle income countries like China and India.

To slay the Goliath of today humanity must be more compassionate, more imaginative, and more inspiring than it has been in the past. Slaying Goliath in the 21st century will require, I believe, an aggressive effort to understand the biology of aging, and then the development of interventions that modulate the rate of aging, so that humans can enjoy more disease-free life and a compression of morbidity at the end of life.

Why we age, and become frail and diseased, is a legacy of our evolutionary history. In short, because life in the state of nature was "nasty, brutish and short" the force of natural selection does not apply to the post-reproductive period of the human lifespan. So most disease and death today are caused by evolutionary neglect. And given the size of today's aged populations, unprecedented numbers of humans will suffer the ravages of chronic disease.

The vision of David battling Goliath came to me today as I happened across the following video this morning and was deeply moved by it. It is an interview with J.M. Smith, an evolutionary biologist who died in 2004. While a student Smith studied fruit fly genetics with J.B. Haldane.

In this interview Smith discusses the illness and death of his teacher, who died of cancer. This brief video moved me in many ways. It captures the human ability to display humour and determination in the face of adversity, as well as love and friendship. It captures humanity's most redeemable qualities, as told by one the greatest scientists of the 20th century.

It is only fitting to quote a passage from Haldane's famous poem on cancer:

I wish I had the voice of Homer
To sing of rectal carcinoma
Which kills a lot more chaps in fact,
Than were bumped off when Troy was sacked

To slay Goliath this century we must build on the work of great minds like Haldane and Smith. We must transcend the "disease model" approach to the medical sciences, and develop Darwinian medicine.

And aging research is at the frontier of this more robust and ambitious vision of medicine. Modifying the biological clocks we have inherited from our Darwinian past would be this century's most important advance in public health. For age retardation would help protect the 2 billion people who will be over the age of 60 by 2050 from the chronic diseases that currently ravage unprecedented numbers of aged people in the world today. In order for this biological revolution to occur we must also undergo a cultural revolution. We need a rational and humane culture. We need more compassion, more imagination and more (new sources of) inspiration.

And we all have a moral responsibility to help spur on this cultural revolution and become 21st century humanists.


Saturday, November 07, 2009

Biogerontology Paper Now Online

My paper entitled "Framing the Inborn Aging Process and Longevity Science" is now published on the "Online First" section of the journal Biogerontology. Here is the abstract:

The medical sciences are currently dominated by the ‘‘disease-model’’ approach to health extension, an approach that prioritizes the study of pathological mechanisms with the goal of discovering treatment modalities for specific diseases. This approach has marginalized research on the aging process itself, research that could lead to an intervention that retards aging, thus conferring health dividends that would far exceed what could be expected by eliminating any specific disease of aging. This paper offers a diagnosis of how this sub-optimal approach to health extension arose and some general prescriptions concerning how progress could be made in terms of adopting a more rational approach to health extension. Drawing on empirical findings from psychology and economics, ‘‘prospect theory’’ is applied to the challenges of ‘‘framing’’ the inborn aging process given the cognitive capacities of real (rather than rational) decision-makers under conditions of risk and uncertainty. Prospect theory reveals that preferences are in fact dependent on whether particular outcomes of a choice are regarded as ‘‘a loss’’ or ‘‘a gain’’, relative to a reference point (or ‘‘aspiration level for survival’’). And this has significant consequences for the way biogerontologists ought to characterise the central aspirations of the field (i.e. to prevent disease versus extend lifespan). Furthermore, it reveals the importance of shifting the existing reference point of the medical sciences to one that is shaped by the findings of evolutionary biology and biodemography.


Friday, November 06, 2009

Gene Therapy Success for Brian Disease

Naturenews reports on another important success for gene therapy-- treatment for ALD (adrenoleukodystrophy), a rare, inherited metabolic disorder that afflicts young males.

ALD results in severe degeneration of the structure that is crucial for brain-cell function and most die before adolescence.

Here is a sample from the news story:

Researchers have halted a fatal brain disease by delivering a therapeutic gene to the stem cells that mature into blood cells.

The gene was transferred using a virus derived from HIV, a technique that researchers have pursued for more than a decade but has not been successful in humans until now.

...."It's a huge advance," says Mark Kay, director of the Program in Human Gene Therapy at Stanford University School of Medicine in California. "If you look in general at the vectors we use for gene therapy, we've really come a long way. This is the first successful use of lentiviral vectors, and it gives me a lot more cautious optimism moving forward."

The research article of the study is published in Science (paper here).


Thursday, November 05, 2009

Science Paper on Dynamics of Inequality

The latest issue of Science has this interesting article on the intergenerational wealth transmission and the dynamics of inequality. Here is the abstract:

Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population’s long-run steady-state level of inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. We estimate the degree of intergenerational transmission of three different types of wealth (material, embodied, and relational), as well as the extent of wealth inequality in 21 historical and contemporary populations. We show that intergenerational transmission of wealth and wealth inequality are substantial among pastoral and small-scale agricultural societies (on a par with or even exceeding the most unequal modern industrial economies) but are limited among horticultural and foraging peoples (equivalent to the most egalitarian of modern industrial populations). Differences in the technology by which a people derive their livelihood and in the institutions and norms making up the economic system jointly contribute to this pattern.