Wednesday, September 30, 2009

Globe Article on Cost of Aging Canada

Jeffrey Simpson has this excellent piece in today's Globe on the cost of Canada's aging population and the reasons why no political party is serious about meeting these challenges. Here is an excerpt:

How far ahead do politicians usually think?

In a minority government, politicians think an hour ahead sometimes, a month more often, a year ahead occasionally. In a majority government, parties have the luxury of preparing for electoral combat in four or five years, and governments can plan for something other than tomorrow's survival.

....What kind of pressure lies ahead?

Pierre Fortin of the University of Quebec at Montreal, one of the very best public finance economists in Canada, tried to tackle the question of how much aging will cost. His answer: about $40-billion a year (in 2008 dollars) by 2020. In other words, in about a decade, even if Ottawa balanced the budget today – let alone run $100-billion in deficits in coming years – it would still be heading into the fiscal hole.

....Who in politics is talking seriously about this demographic fact? Which politicians have you noticed saying: We need to get the federal budget balanced, and then run surpluses as fast as we can after the recession ends, so that our country will be ready for what Prof. Fortin properly calls the “fiscal squeeze?”


Saturday, September 26, 2009

Obesity and Aging Linked

Sometimes it is tricky to make the link between important related (even complementary) societal goals. Over the years I have emphasized the importance of tackling obesity. See, for example, my 3 part post on childhood obesity (here) or my post on how exercise can help prevent depression here.

Over the years I have also exerted a lot of energy emphasizing the importance of tackling aging itself. A search for "aging" on the search function for my blog gives this lengthy list of posts.

Many people would of course agree that obesity is a problem. And thus they would agree that we, as both individuals and societies, ought to tackle obesity in an effort to reduce the risks of heart disease, stroke, diabetes, etc.

Yet when it comes to aging I know most people's attitudes become very different. Either they think (a) talk of mitigating aging (unlike obesity) is pure science fiction (which is what I actually thought before I started to follow the scientific developments in the field); or (b) they think it is unethical to intervene in the aging process.

And so over the past few years I have spent most of time arguing against what Richard Miller calls “gerontologiphobia” which he defines as follows:

There is an irrational public predisposition to regard research on specific late-life diseases as marvelous but to regard research on aging, and thus all late-life diseases together, as a public menace bound to produce a world filled with nonproductive, chronically disabled, unhappy senior citizens consuming more resources than they produce. No one who speaks in public about longevity research goes very far before encountering the widespread belief that research on extending the life span is unethical, because it will create a world with too many old people and not enough room for young folks.

And so I have published articles arguing that sufficiency is an inappropriate principle to invoke for the good of health, I have argued that equality requires us to mitigate age-related disadvantage, I have argued that the time has come to take on time itself, I have argued that the concerns about aggregation that arise in the case of tackling aging are not valid objections to prioritizing aging research, I have argued that we need a more inclusive vision of the medical sciences, and I have argued that it is both rational and reasonable to aspire to decelerate the rate of aging.

So I think the reasons for tackling aging are many, diverse and, most importantly, compelling! And yet the struggle to overcome gerontologiphobia goes on.

Well, this article in the latest issue of Nature Medicine illustrates why the we ought to be consistent in our attitudes towards health when it comes to tackling both obesity and aging. It turns out that obesity actually accelerates aging!

Here is a brief excerpt from the News and Views section on the study:

As technology has improved hygiene, the food supply and living standards overall, there has been a rise in such age-related illnesses as cardiovascular disease, cancer, degenerative diseases of the brain and other organs, and metabolic disorders such as diabetes. Age-related disorders have become widespread throughout the world, replacing infectious diseases as the leading cause of death in developed countries. As we age, many people develop the metabolic syndrome, characterized by central (visceral) obesity, insulin resistance, impaired glucose tolerance or overt diabetes, hypertension, dyslipidemia and cardiovascular complications.

Diabetes is also a recognized cause of accelerated aging, but the mechanisms linking diabetes and aging are not well understood. Work from Minamino et al.1 in this issue of Nature Medicine offers insights into how obesity affects the aging of adipose tissue, influencing inflammation and glucose homeostasis.

...In obese states, adipose tissue is subjected to oxidative stress, resulting in aging, accumulation of macrophages, production of proinflammatory cytokines and suppression of adiponectin. Activation of p53 tumor suppressor is pivotal in the aging process, stimulates inflammation and possibly attenuates the capacity of stem cell renewal. The aging of adipose tissue induces insulin resistance in adipose tissue, liver and muscle and mediates the progression to diabetes.

And here is the abstract of the study:

Various stimuli, such as telomere dysfunction and oxidative stress, can induce irreversible cell growth arrest, which is termed 'cellular senescence'1, 2. This response is controlled by tumor suppressor proteins such as p53 and pRb. There is also evidence that senescent cells promote changes related to aging or age-related diseases3, 4, 5, 6. Here we show that p53 expression in adipose tissue is crucially involved in the development of insulin resistance, which underlies age-related cardiovascular and metabolic disorders. We found that excessive calorie intake led to the accumulation of oxidative stress in the adipose tissue of mice with type 2 diabetes–like disease and promoted senescence-like changes, such as increased activity of senescence-associated beta-galactosidase, increased expression of p53 and increased production of proinflammatory cytokines. Inhibition of p53 activity in adipose tissue markedly ameliorated these senescence-like changes, decreased the expression of proinflammatory cytokines and improved insulin resistance in mice with type 2 diabetes–like disease. Conversely, upregulation of p53 in adipose tissue caused an inflammatory response that led to insulin resistance. Adipose tissue from individuals with diabetes also showed senescence-like features. Our results show a previously unappreciated role of adipose tissue p53 expression in the regulation of insulin resistance and suggest that cellular aging signals in adipose tissue could be a new target for the treatment of diabetes.

OK, so bringing the insights of the link between obesity and aging together with attitudes towards biological aging in general... When it comes to a disease like progeria, which is an extreme form of accelerated aging, I assume we would all agree that we should seek ways of preventing the disadvantage that comes with the disease. No child deserves to be robbed of the opportunity to have a healthy childhood and develop into a healthy adult. Progeria is very rare, affecting about 1 in 8 million births.

When it comes to obesity, which also accelerates aging (though is less severe than progeria, but much, much more prevalent) we also think we should strive to prevent this. No one deserves diabetes or heart disease in their 50's or 60's. But what about the "regular" rate of aging, which is less severe but much, much more prevalent than obesity, what should our attitude be? The inborn aging process limits average life expectancy of humans to around 85. Shouldn't we aspire to retard that rate of molecular and cellular damage if it would help prevent disease and death? Does anyone actually believe people (our to make the point more vivid, their parents, children or spouse) deserve heart disease, stroke, AD, cancer, etc. in late life? The prevalence of gerontologiphobia is among the most perverse features of our culture for it eschews the most importance science of our day. These means aging research is grossly underfunded and that young scientists who want to make the world a better place gravitate towards goals like trying to control the global climate or finding a cure for just one disease of aging (e.g. cancer) rather than investigating the aging process itself.

So this study in Nature Medicine, which suggests there is a link between aging and obesity, shows why our attitude towards aging and obesity ought to be the same. Those who believe that the "obesity status quo" is unacceptable should also view the more general "aging status quo" as unacceptable. Both subject today's populations to high risks of morbidity and mortality, risks we should seek to minimize as far as possible.


Wednesday, September 23, 2009

Evolution and Immunosenescence

As we age our immune system declines. Why is this so? This paper in the June issue of Trends in Immunology tackles that question. Here is the abstract:

There is an accumulating body of evidence that a decline in immune function with age is common to most if not all vertebrates. For instance, age-associated thymic involution seems to occur in all species that possess a thymus, indicating that this process is evolutionary ancient and conserved. The precise mechanisms regulating immunosenescence remain to be resolved, but much of what we do know is consistent with modern evolutionary theory. In this review, we assess our current knowledge from an evolutionary perspective on the occurrence of immunosenescence, we show that life history trade-offs play a key role and we highlight the possible advantages of the age-related decline in thymic function.

And a sample:

Potential pathogens—viral, bacterial, fungal, macroparasite and dysfunctional host cells—present a major threat to survival, and the innate and adaptive immune systems have evolved a series of defence networks to protect the individual from such harmful agents. These systems are not without fault, however, and with increasing age, problems arise in functional activity. There is clear evidence of an age-related decline in effectiveness of the immune systems of vertebrates and some invertebrates, which renders older individuals more vulnerable to infection.

....The adaptive immune system with high specificity to antigens first appeared some 350 million years ago in jawed fish, and its value is demonstrated by the fact that it has been retained, albeit with a variety of modifications, by all vertebrates.

....The force of natural selection declines with age, leading to a particular value being placed on survival to maturity and on reproductive output thereafter. An ability to mount a strong inflammatory response early in life and the finely tuned repression of the immune response to accommodate successful reproduction are clearly in support of this.


The Folly of our Times (Part Two)

This is a continuation of the themes from this previous post.

Of all the incredible things that humans have accomplished, our ability to think rationally and consistently about an uncertain and unpredictable long-term future is not one of our strongest attributes. For the vast majority of human history we had a short life expectancy (under 30 years) and thus the cognitive capacities we have inherited from our Darwinian past reflect the reality that, historically, it was much more important to think clearly about short-term goals (like finding food and a mate) than the complex long-term goals facing societies in the 21st century.

This situation thus creates a real pickle for us once we attempt to tackle very complex, long-term challenges.

Perhaps one of the sagest insights from the history of moral philosophy, which can help us out in such cases, is Jeremy Bentham's "calculus of happiness" (see my previous posts on Bentham here and here). Today I don't want to invoke all of Bentham's calculus, but just 3 important components of rational, long-term priority setting.

(1) We have to come up with some criteria for determining what makes an issue a "BIG" issue. So let's say that "harm", generally construed, helps determine the magnitude of a particular problem. So harm could be disease, death, poverty, etc.

If the harm of A is 10 times larger than the harm of B (say A =10 cancer deaths and B= 1 cancer death), then (all else being equal) A is a much bigger problem than B. Or if the probability of X occurring is only 0.0001% and the probability of Y occurring is 50% then, even if the magnitude of Y is half that of X, Y is a much bigger problem as the expected disutility of Y outweighs that of X. This provides us with a "rule of thumb" by which we can determine what the biggest problems are: the larger and more probable the harm in question, all else being equal, the stronger the imperative to mitigate it (i.e. the higher up on the list of priorities it should be).

(2) Once we have come up with the list of "The Biggest Problems", that is only have the battle. A big problem that you cannot do much about is not a problem worth worrying about too much. So the other important issue to bear in mind when thinking about priorities is the likelihood of success. All else being equal, the greater the chances are that you can actually mitigate the harms in question the greater the case for making the issue in question a higher priority. So if the harms of Y outweigh the harms of X on both the magnitude and certainty criteria, but you can't do anything about Y but could do something about X, it would be irrational to prioritize Y over X.

(3) You must also consider the cost trying to realize the benefits of the intervention in question. Spending all available resources on trying to mitigate the harms of X means you have no funds left for tackling Y and Z and Z'. But if the good realized in mitigating Y, Z and Z' are larger than the good realized in X, it would have been more prudent to tackle less major harms (but more of them) for lower cost.

These three issues- (1) the magnitude and certainty of the harm in question, (2) the probability of a successful intervention and (3) the cost of the intervention- ought to be the central considerations at play in determining societal priorities.

Of course the devil is in the details. It is notoriously difficult to estimate what the long-term consequences of something might be. And there are issues of discounting: do we give equal weight to the interests of those alive now and those that will follow us in a century or millenia from now?

When I reflect upon the issues of what constitutes a harm for humans (as both individuals and collectively as a society), and what it may be possible to do this century if we invest in certain areas of knowledge and innovation, one particular issue stands out far above the rest--- global aging. Why not climate change, the threat of terrorism or an asteroid hitting the planet, you ask? Let me tell you why (though I'll only focus on climate change as that dominates the news today).

(1) First let's take stock of the harms of biological aging. The inborn aging process is the leading cause of disease and death today. But to see that we need to focus on the ultimate (rather than proximate) causes of disease and death. Disease and death are bad for an individual as they jeopardize or remove the opportunities for flourishing. Disease and death are also bad for societies. Dramatic rises in chronic diseases like cancer, heart disease and stroke present enormous challenges to the economic prosperity of a country.

So the magnitude of the harms of senescence are unprecedented in human history (in terms of the number of people negatively affected by it).

Furthermore, these harms are a 100% certainty if we do not modify the aging process. We don't need computer models to accurately predict that middle aged people today will age and become frail. Unless an infectious disease comes along and kills today's young and middle aged, they will live to be tomorrow's aged persons and they will suffer the same chronic diseases of late life that killed their parents.

Contrast this with the magnitude and certainty of the harms of climate change. The climate is of course always changing. But unlike biological aging, that leads to an exponential increase in risk of morbidity and mortality, when the climate warms or cools a few degrees it brings a complex mix of harms and benefits. Warmer temperatures could boost agricultural production in certain regions of the world (like Russia), but harm agricultural production in other areas. With respect to infectious diseases like malaria (see here), warmer temperatures will result in lower risk of malaria for some areas as temperature fluctuation around means >21°C slows parasite development, whereas fluctuation around <21°C speeds development. So changes in climate are not "unconditionally" good or bad. There are some good things for some people, and some bad things for others. And it is immensely difficult to anticipate what any of these will be 50 or 100 years from now.

And observing temperatures is not like observing biological changes in a mammal. We can accurately predict what will happen to most humans after the age of 80 (they will become more frail and suffer one of the diseases of aging and most likely die before age 100). But the climate? Predictions are on much, much more precarious grounds. Even though we still have a lot to learn about human biology, we are light years ahead in our understanding of human biology than we are with understanding what influences global temperature (humans are complex, but the not as complex as all of the external enviroment). There is no climate science equivalent to Darwin's Origins of the Species that was published over 150 years ago and has withstood more than a century of rigorous scientific testing. So climate science is an infantile science. To say that is simply to state a fact (so critics who claim it is "anti-scientific" don't understand what science actually is). The main reason climate science enjoys the popularity and influence it now enjoys is because it has become policitized. It is not because of major scientific breakthroughs in our knowledge of the workings of the climate.

This is not to say there are no important issues worth investigating here and that these insights shouldn't inform policy. I believe there are. But the confidence many have in the magnitude and certainty of the potential harms in question are unfounded and are simply scare tactics that, like the "war on terrorism", people use to persuade people to accept when they have little else to invoke. Taken in the abstract, the harms of climate change might appear enormous and probable. But when placed in the context of all the other things that can occur this century, they are less prominent and concerning.

But perhaps the greatest contrast between prioritizing the effort to retard global aging rather than global warming concerns criteria (2) and (3) noted above. Let's start with (2). Is there reason to believe we could retard aging, thereby increasing the human healthspan and compressing morbidity and mortality at the end of life? Yes. Since the 1930's we have known that calorie restriction extends the lifespan of a variety of different organisms (e.g. yeast, fruit flies,), including mammals. More recently "longevity genes" had been identified. And the first human clinical trials involving anti-aging molecules are already under way.

How many experiments have we done to see if humans can control global temperatures? 0.

Now consider (3). How much would it cost to make serious headway on aging? Proponents of the "Longevity Dividend" campaign recommend a $3 billion investment. Slowing aging by just 7 years would reduce the risk of disability, disease and death by 50% at every age in adulthood. Whereas the Stern Report recommends spending 1% of global GDP each year to reduce greenhouse gas emissions. Looking up the global GDP for the year 2008, that would put the investment for 2008 at $600 billion dollars. And this would of course rise over the next two decades as the global GDP rises. So advocates of tackling climate change are proposing we (including poor countries, I might add) spend much, much more money trying to mitigate smaller and less certain (and immediate) harms that are premised on a more imcomplete observational science. Such a project would amount to the most expensive scientific experiment in human history. And it would be the first time any such "climate experiment" would be pursued.

So the way I see it, we face a choice. Those that want to create the greatest good for those alive today and those to come in the future can champion one of two causes as the defining cause of our times:

Cause #1 Slowing global aging
Cause #2 Slowing or reversing climate change

The certainty and magnitude of the harms of permitting the status quo with respect to aging far outweigh what will occur with respect to climate change. Secondly, as both an observational and experimental science, biogerontology is much, much further advanced than climate science. And so the likelihood of the benefits of doing something about #1 is much higher than #2. And the magnitude of the potential benefits are also much higher. And finally, in terms of cost-- reprogramming the human metabolism via a drug that mimics the effects of CR will cost a lot less than aspiring to control the climate.

So the real debate we need to have today is this: Which cause ought to be the greater priority- decelerating human aging or trying to control global temperatures. For me at least, the choice is clear.


Friday, September 18, 2009

Life Expectancy, Priorities and Aging Research

There are many different ways to arrive at a list of the top priorities a society should set for itself. One could set priorities based on the intuitions or "gut instincts" people happen to have at any given time. Or, alternatively, one could base priorities on the empirical data we have concerning what harms individuals and societies and what the magnitude of the benefits of mitigating such harms would be. I prefer the latter approach.

Indeed it is my preference for the latter that leads me to be a strong advocate for aging research rather than an advocate for tackling terrorism, trying to control the climate, etc. Most people alive today will most likely develop, and die from, one of the chronic diseases of aging like cancer, heart disease or stroke.

So tackling chronic disease is the greatest challenge of this century. However, unlike infectious diseases, eliminating any one chronic disease will have a minimal impact on a population's health prospects. Why? Because of the fact of co-morbidity. "Now that comorbidity has become the rule rather than the exception, even if a “cure” was found for any of the major fatal diseases, it would have only a marginal effect on life expectancy and the overall length of healthy life" (source)

To drive home the reality of co-morbidity, and the challenges it raises for promoting the health of aging populations, take a look at the United States life tables for eliminating certain causes of death here (it's a bit dated (1990)... if anyone can find a more recent version of this life table with gains for eliminating causes of death please let me know).

Let's start first with Table A. "Probability at birth of eventually dying from specified causes of death by race and sex: United States, 1989–91". The probability (for the total population at birth) of dying from infectious and parasitic diseases in the US is 2%. Death in car accident 1.4%. Homicide 0.7%. Sudden infant death syndrome 0.13%. The highest probabilities are the chronic diseases that mostly afflict the aged. Probability of dying from cancer is 22%, and for cardiovascular diseases (e.g. heart disease and stroke) the probability is 47%.

These statistics make vivid what is the greatest threat to the health prospects of a population- chronic diseases- and who is most at risk (i.e. those over the age of 60).

But suppose we eliminate a specific disease. How much would this increase life expectancy at birth? Scroll down to Table 22. Gain in expectation of life due to elimination of specified causes of death, by exact age for the total population for the answer. If newborns in the United States were born into a society with 0% risk of infectious disease life expectancy would increase by 164 days. With 0% risk of ever developing cancer life expectancy would increase by 3.36 years. With 0% risk of Alzheimer's disease life expectancy for the coherent born today would increase by 18 days. For a baby born today who would survived long enough to die from AD, they would live an extra 6.8 years if AD was eliminated. And with no major cardiovascular diseases to kill you life expectancy would increase by 6.7 years, which is 1.5 years more than the difference in life expectancy between being born female rather than male.

The striking thing about these gains in life expectancy is how low they really are. We just assume a world with no cancer would dramatically increase life expectancy, but this is not so. Of course a cure for an early onset disease would result in large benefits to the life expectancy of those who would die from that specific disease (and those stats are also there). But the reason the numbers are not bigger is that eliminating one cause of death in late life simply delays the time one will most likely develop another disease of aging (the reality of co-morbidity). So if you don't die from cancer in your 80's you most likely have a stroke or heart disease, etc.

These kinds of data should be the basis of a rational approach to health extension. And that is why aging research ought to be a top priority today. Retarding aging would help us delay all age-related disorders simultaneously, thus yielding healthy dividends that far exceed what a cure for cancer or AD or stroke could yield. So one of our top priorities should be to increase the health prospects of humans in late life. Thus aging research ought to be at the top of our priorities.


Thursday, September 17, 2009

Where the Action As: On the Site of the Playful Life (as told in song)

Recently I have posted a series of posts on the importance of play. But Cat Stevens makes the same points much more concisely and effectively in the form of song. Enjoy.


Gene Therapy for Colour Blindness

NatureNews has this story about how two monkeys had their colour vision restored with gene therapy. Here is a brief excerpt:

Neitz and his colleagues introduced the human form of the red-detecting opsin gene into a viral vector, and injected the virus behind the retina of two male squirrel monkeys — one named Dalton in honour of the British chemist, John Dalton, who was the first to describe his own colour blindness in 1794, and the other named Sam....

After 20 weeks, the monkeys' colour skills improved dramatically, indicating that Dalton and Sam had acquired the ability to see in three shades (see video). Both monkeys have retained this skill for more than two years with no apparent side effects, the researchers report in Nature1.

Adding the missing gene was sufficient to restore full colour vision without further rewiring of the brain even though the monkeys had been colour blind since birth. "There is this plasticity still in the brain and it is possible to treat cone defects with gene therapy," says Alexander Smith, a molecular biologist and vision researcher at University College London, who did not contribute to the study.

"It doesn't seem like new neural connections have to be formed," says Komáromy. "You can add an additional cone opsin pigment and the neural circuitry and visual pathways can deal with it."


Wednesday, September 16, 2009

Study on Genes and Age of First Sexual Intercourse

The latest issue of Child Development has this interesting study which suggests that genetics plays an important role in explaining why children raised in homes without a father are more likely to have sex earlier than those raised in homes with a father. This study illustrates how complex the interaction between our environment and our biology really is, and how far we still have to go in terms of our understanding of the different things (like the genes we inherit from our parents) that influence human behaviour. Here is the abstract of the study:

Children raised without a biological father in the household have earlier average ages of first sexual intercourse than children raised in father-present households. Competing theoretical perspectives have attributed this either to effects of father absence on socialization and physical maturation or to nonrandom selection of children predisposed for early sexual intercourse into father-absent households. Genetically informative analyses of the children of sister dyads (N = 1,382, aged 14–21 years) support the selection hypothesis: This association seems attributable to confounded risks, most likely genetic in origin, which correlated both with likelihood of father absence and early sexual behavior. This holds implications for environmental theories of maturation and suggests that previous research may have inadvertently overestimated the role of family structure in reproductive maturation.

And here is a sample from the EurekAlert! on the study:

Previous research has found that children raised in homes without a biological father have sex earlier than children raised in traditional nuclear families. Now a new study that used a novel and complex design to investigate why this is so challenges a popular explanation of the reasons.

Among prior explanations of why children who live in homes without fathers have sex earlier are that early childhood stress accelerates children's physical development, that children who see their parents dating may start dating earlier, and that it's harder for a single parent to monitor and supervise children's activities and peers. All of these are environmental explanations.

"Our study found that the association between fathers' absence and children's sexuality is best explained by genetic influences, rather than by environmental theories alone," according to Jane Mendle, assistant professor of psychology at the University of Oregon, who led the study.


Sunday, September 13, 2009

Political Theory and Aging Research

As a political theorist who works on issues that intersect the biological sciences and medicine, I frequently get puzzled looks when I tell students and colleagues I am working on aging and longevity science. Their puzzlement is understandable, as these topics do not currently receive much attention in the discipline.

When we one thinks of the subject "the study of politics", we tend to think of voting behaviour and political parties, or institutions like the Supreme Court or Congress. It is only natural to associate the study of politics with the study of the issues that dominate the evening news- so high-profile government decisions like the war on terror, the economic bailout or tackling climate change.

Images like these three thus capture the stakes and concerns we currently associate with the study of politics:

These images resonate with our understanding of political science. Political scientists are interested in power: what is it?, who has it?, how do different institutions and cultures influence power?, and when (if ever) can power be legitimate? The different sub-fields of political science reflect the diversity of concerns that arise here- comparative politics, international relations, political theory, etc.

While these images and sub-disciplines are important and cover many diverse issues, I also think it is important for us, as political scientists, to critically reflect upon the adequacy of the tools and concepts we utilize to adequately diagnosis the pressing challenges we face today in the twenty-first century.

The first (and in my opinion the best) political scientist was the Ancient Greek philosopher Aristotle. For Aristotle politics is a normative practical science. The primary concern of politics is the good of humans. And this made politics the most authoritative of all the sciences as the political scientist could prescribe which sciences ought to be studied (e.g. economics, biology, etc.).

Aristotle inspires me, and when I reflect upon the current state of contemporary political theory I feel we have forgotten how sage Aristotle's insights are. A concern with the good of humans has given way to the concerns which the professionalization of the discipline places a premium on- like narrow specialization. The puzzlement I encounter when I tell people I am a political theorist who has an interest in aging and longevity science confirms this sad state-of-affairs. Unlike Aristotle, who was genuinely concerned with the good of humans and had a curious intellect that ranged across many different disciplines (philosophy, biology, politics, etc.), political theory in the twenty-first century reflects the constraints and incentive structure of academia. The concern for tenure and promotion and RAE submissions underlies a great deal of the research in the field today. And this creates pressures to become more and more specialized and risk-adverse. If there is a sub-field in political science that should not be overtly specialized and risk-adverse it is political theory.

So when I reflect upon the state of contemporary political theory the thing that strikes me most is how parochial and atemporal we theorists have become. Debates in theory move slowly, very slowly. In some ways this is a good thing. Theorists like to take our time to think things through. This is important. Rushing things usually doesn't yield sage insights. There are often subtle, yet important, distinctions and provisos that need to be made. So I want to emphasise that I recognise that and agree it is important.

However, the pace of technological innovation today means that novel and unprecedented challenges face humanity. Challenges that theorists ought to be investing their thoughts and energies into tackling. And, at least for me my tastes, we are moving too slowly, and our focus is too narrow. This inertia stems mostly from the fact that we wear "blinders" that shield us from the realities of today's world and the new knowledge which evolutionary biology yields. Aristotle would scoff at the insularity and specialization of contemporary political theory. While concerns for the good of humans do populate debates in the field (some more than others), that concern is peripheral rather than central.

The neglect of science and technology, for example, easily illustrates how wide the gap is between debates in political theory and the real world. If you were born 200 years ago you probably wouldn't live to see your 30th birthday. If you are born today you will most likely live long enough to suffer from one of the chronic diseases of aging in late life (after age 60). We have more than doubled the life-expectancy of humans in just 200 years. And yet the significance of the advances that made this possible- like the sanitation revolution, vaccinations, material prosperity, changes in behaviour, etc.- go largely unnoticed by the political theorist. Such "macro-level" considerations typically aren't on the radar of theorists because we tend to form our theories and principles on the basis of micro-level considerations (e.g.: "Look, the Jones's have more money than the Smith's do. Is this inequality in one small dimension of their life prospects fair if it is the result of "brute luck"?)

So, how does one go about linking political theory to aging research? This is my project. It is one that constantly weighs on my mind given that one does not encounter journal articles on this topic, nor conferences addressing these themes, etc. But this challenge helps sharpen my intellect. If I chose to work on multiculturalism or global justice I wouldn't have to justify my chosen topic to anyone. Those are topics almost all theorists work on. And thus one can just display the "membership" badge to the club and proceed with little or even no justification for why one has chosen to work on these topics.

So tackling something new or neglected in a field comes with risks. Maybe others don't write on this topic because it actually is unimportant. I have taken this prospect very seriously. But after researching these topics for the past few years my confidence in the importance of aging research, for both society and political theorists, has grown. There will be 2 billion humans over age 60 by mid-century and these people will be at a high risk of chronic disease. We live in an "aged-world". A world where most humans alive today will die from the diseases that afflict us in old age. Death and disease are very serious things. They ought to be among the top few things on our list of what undermines the good of humans. And this means we ought to place a premium on the knowledge and innovation that could help us alter the biological clocks we have inherited from our evolutionary history.

Even though the evening news does not report breaking headlines concerning the unprecedented numbers of people suffering chronic disease does not mean it is not an important issue worthy of serious study and reflection. Rather than have the media shape my research interests, or simply follow the existing trends in my field, I have adopted a different approach (at least for this stream of my research). To see why aging is so important I want you to consider the importance of fossil records. If we examine the fossil records of our distant ancestors from thousands of years ago we see what posed the greatest threats to their health and prosperity. The fossil records of our distant ancestors reveal the toll inflicted by violence, poverty and infectious disease. Very few humans lived long enough to suffer from the chronic diseases of aging.

The fossil records from the twenty-first century, however, will reveal something truly unique in human history- that the inborn aging process is now the leading cause of disease and death. Of course it's possible that an asteroid could destroy humanity this century, or we could destroy ourselves in a nuclear war. But the most likely scenario is that most humans alive today will die from cancer, heart disease and stroke, and these diseases will kill them after the age of 60. These future projected fossil records, rather than the evening news or a chapter in Rawls's A Theory of Justice, is what shapes my thinking about these issues. But we may be able to alter this likely future. It is irrational for humanity to ignore the leading cause of disease and death. Of all the things to ignore, the last thing should be the leading cause of disease and death!

So, let me be more precise as to why this matters to us political theorists. Much of course depends on what we take political theory to be. Recall my account of what theory is. Here is an excerpt from that earlier post:

Dunn claims that the purpose of political theory is to diagnose practical predicaments and to show us how best to confront them. Doing this, he adds, requires us to develop the following three distinct 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)

So the theorist in me says that understanding our evolutionary biology and aging research apply to all of these. Let me fill in the relevant details.

1. How did we get to the situation where 220 million humans will die from the chronic diseases in just the 10 years from 2005-2015? The first part of the story is the story of the triumph of human ingenuity. Over the past 200 years we have been able to increase life expectancy at birth from below 30 to over 67 years by reducing early and mid-life mortality. This has been an amazing accomplishment. Yet it is important to recognise that preventing death and disease early in life has brought about the dramatic rise in population and age-related disorders. Why do we age? And why does aging make us vulnerable to frailty, disease and death? To make a long story short- because 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 populations, unprecedented numbers of humans will suffer the ravages of chronic disease.

2. What is the ideal? Less disease, more health!

3. How to get there? To put things very generally- We need to think outside the box. The medical sciences are currently dominated by the "disease-model" approach to health extension. This approach is costing more and more money, and yielding smaller health dividends. The real culprit is aging itself. Retarding aging would bring individuals and societies greater opportunities to flourish. For political theorists we must transcend our fixation on the distribution of external goods like wealth and income and take more seriously the natural determinants of health. Rather than start from Rawls's A Theory of Justice we should start from Darwin's Origins of the Species. Rather than assuming all members of society are healthy and productive we should strive to understand the constrains which an aging population face. Rather than bury our heads in the sand with respect to science we must stay abreast of the incredible progress being made, especially in the biomedical sciences.

This has been a long post. Thanks for your patience in permitting me to work these issues out in my own mind as I attempt to strengthen my case to get political theorists to take people for what they really are (Part 1, Part 2, Part 3).

So I want to finish by appealing to my fellow theorists to take more seriously the importance of images like these:

These images illustrate the real challenges of the 21st century. With adequate funding, creativity and innovation, today's governments might help us achieve one of the most laudable of goals- modulating the biological clocks we have inherited from our evolutionary history. The sooner we begin to think seriously about addressing this issue the better.


Wednesday, September 02, 2009

Happiness, Success and Genetics

The American Journal of Sociology has an interesting issue on "Exploring Genetics and Social Structure". This paper considers the influence of genes on happiness and success. Here is the abstract:

Although there is considerable evidence linking success—including wealth, marriage, and friendships—to happiness, this relationship might not reflect, as is often assumed, the effects of the proximate environment on well‐being. Such an interpretation is contravened by evidence that both happiness and the environment are influenced by genetic factors and family upbringing. Using the National Survey of Midlife Development in the United States, which includes a subsample of twins, this study evaluates the relationship between happiness and various features of success before and after eliminating the influence of endowments. The results suggest that many putative indicators of the environment are highly heritable and, indeed, that the same genes that affect the environment may affect happiness as well. Yet the results also suggest that the role of genetic endowments varies considerably across different features of success, suggesting complex patterns of selection, reinforcement, and causation among genes and the environment.

And a sample:

Despite this evidence, most sociologists continue to emphasize the proximate environment and to empirically unravel its many elements... Even among those interested in genetic influence, most focus on interpreting heritability appropriately, rather than examining the implications of heritability for theories of environmental influence (for an exception, see Guo and Stearns 2002). The former enterprise is laudable and informative, but the latter is more promising insofar as it allows sociology to speak to other disciplines in an emerging transdisciplinary dialogue.

In this study, I seek to reevaluate the relationship between success and happiness in light of endowments, and I do so with an eye toward sharpening sociology’s theoretical apparatus. I explore a variety of features of success, focusing on those features that have been most central to the discipline, including marital status, schooling, income, and occupational self‐direction. For leverage against endowments, I use data consisting of unrelated individuals, ordinary siblings, and identical twins.

....A more general point is that the serious consideration of genes hardly undermines the relevance of sociology and, indeed, might allow sociologists to address the kinds of action/structure questions that have long animated the discipline. To be sure, current research on social structure and personality has explored how individuals select themselves into environments in ways that promote or hinder their well‐being (see McLeod and Lively 2007). Yet, even when demonstrating the importance of selection, sociologists have generally shown little appreciation of the origins of this action or the strategy it reflects. Genes are useful in this regard in that they provide a mechanism for understanding how individuals respond to and shape their environment, and, as demonstrated here, investigating genes hardly obviates the importance of the environment. Among potential engines of action reflected in genes are personality, tolerance of risk, cognitive abilities, and time preferences (see Freese 2008).