The view from the top of the hierarchy of evidence
1 Oct 2019
About five years ago I began doing meta-analyses. (If, as they say, you lose a tooth for every meta-analysis you conduct, I am now gumming my way through my food.) I was inspired by their growing role as the premier source of evidence in the health and behavioural sciences. Yes, I knew, individual studies are low-powered, depend on very specific methodological assumptions, and are often badly done; but I was impressed by the argument that if we systematically combine each of these imperfect little beams of light into one big one, we are sure to see clearly and discover The Truth. Meta-analysis was how I proposed to counter my mid-life epistemological crisis. I was therefore depressed to read a paper by John Ionnidis, he of ‘Why most published research findings are false’ fame, on how the world is being rapidly filled up with redundant, mass produced, and often flawed meta-analyses. It is, he argues, the same old story of too much output, produced too fast, with too little thought and too many author degrees of freedom, and often publication biases and flagrant conflicts of interest to boot. Well, it’s the same old story but now at the meta-level. Just because … Continue reading “The view from the top of the hierarchy of evidence”
Hanging on to the Edges book published
25 Oct 2018
I am delighted to be able to say that my new book Hanging on to the Edges is now published. Thanks to Open Book Publishers, it’s an open access book; you can read it online, download the PDF, or order paper copies here. People often ask me what Hanging on to the Edges is about, and it is not entirely easy to say. It is based on fourteen blog essays I published on this site over the past two years, though they are revised and re-ordered in the book version. It is an attempt to reflect on the major things I care about most in life: science and being a scientist; human nature and human cognition; the relationship between the social and the biological; inter-disciplinarity; politics; and human well-being. To give you some idea of the scope, here’s a word cloud of the terms in the index: And here’s the table of contents: Contents Introduction PART ONE 1. How my theory explains everything: And can make you happier, healthier, and wealthier 2. What we talk about when we talk about biology 3. The cultural and the agentic 4. What is cultural evolution like? 5. Is it explanation yet? PART TWO 6. The mill … Continue reading “Hanging on to the Edges book published”
HOTTE #14: Morale is high (since I gave up hope)
15 May 2018
Buddhism and the replication crisis: morale is high (PDF) Click here to return to the Hanging On To The Edges hompage.
HOTTE #13: Is it explanation yet?
17 Apr 2018
A meditation on Newtonian mechanics, ‘life-history theory’, and optimal bus networks. Is it explanation yet? (PDF) Back to Hanging On To The Edges homepage
HOTTE #12: The worst thing about poverty is not having enough money
21 Mar 2018
Casinos, helicopter money, and the illusion of validity. The worst thing about poverty is not having enough money (PDF) Return to Hanging On To The Edges
HOTTE #11: Getting your head around the Universal Basic Income
13 Feb 2018
Big ideas, money for nothing, and the psychology of sharing out Getting your head around the Universal Basic Income (PDF) Back to the Hanging On To The Edges page
HOTTE #10: Waking up and going out to work in the uncanny valley
16 Jan 2018
‘The only thing worse than not getting cited is getting cited’, and other inter-disciplinary conceits: Uncanny valley.pdf Back to the Hanging On To The Edges page
HOTTE #9: The need for discipline
4 Dec 2017
A meditation on disciplinary boundaries, small worlds, and choral singing The need for discipline (PDF) Back to the Hanging On To The Edges page
HOTTE #8: What is cultural evolution like?
30 Oct 2017
A meditation on cultural Darwinism, evolutionary theory, and cross-country running. What is cultural evolution like (PDF). Return to the Hanging on to the Edges homepage.
HOTTE #7: Staying in the game
25 Sep 2017
A meditation on the highs and lows, the longs and shorts, of academic life. Staying in the game (PDF). Return to the Hanging on to the Edges home page.
Another great essay!!! Really insightful analysis of issues of so diverse natures. Most interesting for me, since it concerns a personal belief, that the provision of health care should be the number one function of a government. Also, a sound reasoning on the problems faced by science communicators on the use and abuse of the information provided by them. Looking forward to more of your views on that subject.
Hats off to the Mayr citation!
Hi Daniel, enjoying these very much. They are the perfect nap time reading (Penny’s not mine) to give my mat leave squidgy brain a bit of a workout. Looking forward to reading the next instalment. Hope you are well. Take care
Daniel,
I very much enjoyed your essay and think your diminishing returns (DR) argument is a strong one.
I guess you know this but wanted to simplify your essay: increasing the dispersion of income under DR doesn’t necessarily reduce average health outcome. It would do so if the increase in dispersion were symmetric (equally great in the rich and poor directions). If asymmetric, an increase in the high income direction, with its consequent small improvement in health outcome, would have to be large enough to outweigh the relatively large detriment to health outcome due to any decrease in the value of the lowest incomes. Unlikely perhaps but mathematically possible.
A second thought is that the mere fact that greater income brings better health outcomes means that the poor suffer unfairly and we should try to lift people out of poverty (and In a relatively closed system like a nation state this means taking from the rich). This conclusion holds whatever the shape of the function between income and health (linear, DR or whatever). To the extent that Wilkinson & Pickett’s hypothesis is correct their mechanism is an additional way in which inequality results in the poor suffering unfairly, since any stress resulting from perceived societal inequality must surely fall more strongly on the disadvantaged (and you point to evidence for this).
Concerning the “profound unease” of your last few paragraphs I also prefer the stumbling naivety you refer to, openly acknowledging our scientific uncertainty about complex social phenomena. This is not only more honest but, in the long-term I believe, more effective in driving change. Since there will always be other academics to dispute an oversimple claim an apparent ‘controversy amongst the experts’ can be used by policy makers who wish to deny the evidence. And sometimes academic disagreements are relatively unimportant to a case for social change; in the present case of income and health outcomes it might be more effective, as I implied above, to put aside the inequality concept altogether and focus instead on the case for improving the health of the poor by reducing poverty. Of course it is difficult in this argument to avoid comparison with the rich but to the extent that a comparison must be made ‘unfairness’ may be a more broadly acceptable moral label than ‘inequality’. And although, as you say Daniel, the DR argument is more complicated than Wilkinson & Pickett’s, it is a powerful and, I believe, sufficiently understandable point to be used effectively in making the case for the health benefits of reducing poverty (and you say this too). Finally, a purely societally selfish reason for improving the nation’s health is that it reduces pressure on the resources of the National Health Service.
Best, John
John,
Thanks for your helpful and thoughtful comments.
I guess you know this but wanted to simplify your essay: increasing the dispersion of income under DR doesn’t necessarily reduce average health outcome. It would do so if the increase in dispersion were symmetric (equally great in the rich and poor directions). If asymmetric, an increase in the high income direction, with its consequent small improvement in health outcome, would have to be large enough to outweigh the relatively large detriment to health outcome due to any decrease in the value of the lowest incomes. Unlikely perhaps but mathematically possible.
That’s true enough, but I was considering only increases in dispersion that leave the mean income unchanged. I think the asymmetric case you are thinking of would also shift the mean income up (if the total positive gain were greater than the total loss). And the inequality argument is really all about increases in dispersion given a fixed mean – clearly if the whole distribution goes up then even if it goes up unevenly, average health could improve.
A second thought is that the mere fact that greater income brings better health outcomes means that the poor suffer unfairly and we should try to lift people out of poverty (and In a relatively closed system like a nation state this means taking from the rich). This conclusion holds whatever the shape of the function between income and health (linear, DR or whatever). To the extent that Wilkinson & Pickett’s hypothesis is correct their mechanism is an additional way in which inequality results in the poor suffering unfairly, since any stress resulting from perceived societal inequality must surely fall more strongly on the disadvantaged (and you point to evidence for this).
Absolutely – and of course DR and Wilkson and Pickett’s process are not mutually exclusive.
Concerning the “profound unease” of your last few paragraphs I also prefer the stumbling naivety you refer to, openly acknowledging our scientific uncertainty about complex social phenomena. This is not only more honest but, in the long-term I believe, more effective in driving change. Since there will always be other academics to dispute an oversimple claim an apparent ‘controversy amongst the experts’ can be used by policy makers who wish to deny the evidence. And sometimes academic disagreements are relatively unimportant to a case for social change; in the present case of income and health outcomes it might be more effective, as I implied above, to put aside the inequality concept altogether and focus instead on the case for improving the health of the poor by reducing poverty. Of course it is difficult in this argument to avoid comparison with the rich but to the extent that a comparison must be made ‘unfairness’ may be a more broadly acceptable moral label than ‘inequality’. And although, as you say Daniel, the DR argument is more complicated than Wilkinson & Pickett’s, it is a powerful and, I believe, sufficiently understandable point to be used effectively in making the case for the health benefits of reducing poverty (and you say this too). Finally, a purely societally selfish reason for improving the nation’s health is that it reduces pressure on the resources of the National Health Service.
I agree with all of this. And I also think that we need to be more open about our uncertainties, so that the media and public comes to appreciate that some uncertainty in complex scientific matters is the norm. That way ‘the experts disagree’ cannot be used to dismiss the case for action–as if the case where experts disagreed was somehow atypical. We need people to understand that experts always disagree in details of the specifics; but nonetheless there is often broad consensus shining through that disagreement, in cases like climate change and the health consequences of poverty, things that we can all agree on the need for.
Thanks again
Thanks for your response Daniel. On my first point yes, of course you’re right, for this analysis you need to keep the mean income constant, as Wilkinson & Pickett did in theirs. And in this case dispersion of income must change symmetrically and so, given diminishing returns, mean health outcome will decline as dispersion increases.
Total agreement on the final point. And there’s a long way to go in the understanding of science by the public, policy makers and politicians; and the last of these have a vested interest in maintaining (or pretending) some level of ignorance.