The amateurism of modern journalism : a small example

A couple of days back, I discussed how startlingly amateurish journalists can be sometimes. A good example of this can be seen right now in relation to a subject that I've raised on this blog in the past - Dr. Aubrey de Grey's predictions that a breakthrough in life extension technologies may be made in the next few decades. If you type his name into the Google news search function, you'll see a flurry of uncannily similar news reports from the last 24 hours, all of which seem to have been modelled on a single report from Reuters. Nothing wrong with that, so long as the journalists concerned have checked for accuracy. But as it is, many of the articles contain an identical error. For instance, this is from the Daily Mail -

"It's a milestone that few, if any, of us expect to reach.

But the first person who will live to see their 150th birthday has already been born, according to a leading scientist.

Even more incredibly, Aubrey De Grey believes that the first person to live for 1,000 years will be born in the next two decades."

And this from Opposing Views -

"A British doctor claims we are not too far away from virtually living forever -- in fact, he thinks the first person to live 1,000 years will be born in our lifetime."

In reality, as the quickest of internet searches would have revealed, de Grey has been saying for many years that he thinks the first 1000-year-old has probably already been born, and indeed may now be in the latter half of middle age. In this case, the journalists are potentially doing him a favour by (unwittingly) toning the prediction down, because the boldness of his claim tends to encounter instinctive resistance, but even so it's a very sloppy reporting error. So how did it happen? Presumably, de Grey told Reuters that the first 150-year-old had probably already been born, and that the first 1000-year-old was probably less than twenty years younger than that person. Someone then put 2 and 2 together, made 22, and took that as an indication that the first 1000-year-old was due to be born in the next twenty years. A whole series of news outlets went on to take their cue in herd-like fashion.

This sort of thing is, alas, scarcely uncommon in journalists' reporting of pronouncements by scientists. At the height of the BSE scare, every new snippet of information was heralded by hysterical headlines suggesting either that millions were about to die, or that the problem was now completely over - in spite of the fact that the information itself was almost always extremely ambiguous. It seems that many journalists are simply allergic to ambiguity, nuance or detail - but even if that won't be changing any time soon, it would at least be a start if they actually wrote their own articles from scratch, rather than using a ready-made template and very superficially "putting it into their own words".

Since when was a 0.32% risk unacceptable?

Without necessarily endorsing the point she is making about abortion, I have a lot of sympathy with how Cristina Odone reacted upon being told that becoming a mother at the age of 42 was a bad idea...

"My jubilation – I had given up all hope of having a child – overcame any practical considerations, such as would Edward be equally happy at the prospect of parenthood, and would I have to work part-time? So I was taken aback when many of my women friends reacted to my news with: “Is this wise?”

What they really meant was: “Is this convenient?” Such thinking is, in part at least, behind the one-third increase in abortions in the over-forties over the past decade. Age certainly correlates with foetal health; but it is only one consideration."

And it isn't necessarily just prospective mothers who have to put up with that kind of reaction. The most bizarre blog I've ever come across (and the competition is naturally stiff) was written by a woman whose sole purpose in life seemed to be to browbeat men over the age of roughly 30-32 into refraining from having children - because of the elevated risk of autism. It was helpfully divided into categories with catchy and subtle titles along the lines of "Older Men Should Not Start Families" and "Men Should Only Have Children Between the Ages of 20 and 32". Well, my own parents were both well into their forties when I was born, and speaking personally I'm actually quite glad they went through with it in spite of the terrifying 0.32% chance that I would turn out to be autistic (which would scarcely have been the end of the world anyway).

I suppose what might just about be reasonable is to educate school pupils about the potential benefits of having children at a younger age, so they can go on to make informed choices at every stage of their adult lives. But, in the real world, lives and relationships simply refuse to adhere to military-style planning, so to effectively scream abuse at people for 'irresponsibly' deciding to have children at a perfectly normal age seems vaguely ludicrous, not to mention...well, fascistic.

The real question the nuclear lobby will have to answer

The safety issues surrounding nuclear power will always be rather complex, because the illnesses that may be caused by less-than-instantly-lethal doses of radiation take years to show up, by which time it's possible to also attribute them to other factors. Even with a disaster on the unimaginable scale of Chernobyl, experts can't seem to agree whether the number of deaths caused directly by the incident was more in the region of 100 or 100,000. With lower-grade accidents of the type we've had in this country, there has also been a wide range of uncertainty about the long-term consequences.

The nuclear lobby seem to imagine this ambiguity plays into their hands - they can point to the lowest figure of deaths for each incident, and fall back on the trusty phrase "there is no evidence to suggest..." to wave away concerns about higher estimates. I'm not so sure that will wash. For one thing, the uncertainty about the consequences of mid-level releases of radiation directly feeds into the precautions that are - perfectly rationally - taken in the event of an accident, as currently seen in Japan with the evacuation of hundreds of thousands of people from their homes in a state of intense fear, and with children and babies having to be tested for radiation exposure. The first question the nuclear lobby will have to answer in the coming days is not about the intangible issue of long-term health risk following an accident, but rather the very down-to-earth query of "do we really want a building ten miles from our homes that will put us through all that?". Wind farms may spoil the view, but they rarely have a practical and psychological impact quite this profound.

The discombobulation of being on the 'wrong' side of the argument

My post yesterday about Joan Bakewell's BBC article on aging research was picked up by the Fight Aging website, and I must admit I was slightly startled by the comments it attracted. Evidently life extension is a prospect that strongly appeals to many right-wing libertarians, ie. precisely the sort of people I've spent a fair bit of the last two years battling on the topic of gun control. It's slightly disconcerting to find yourself seemingly arguing the same corner as people you're in general ideologically opposed to, and in my case it's happened before on certain issues relating to gender politics, civil liberties, and to a very limited extent abortion (although in the latter case the partial agreement would probably be more with the non-libertarian right). It always tends to make me step back and question whether there's some inconsistency in my thought-processes that I hadn't previously spotted.

However, on this subject I don't see why there actually needs to be an ideological divide, at least at this stage. The bulk of the left are united with the bulk of the right in generally favouring scientific progress as long as it is ethically acquired. The true division will arise if and when anti-aging therapies actually become available, and we need to collectively decide what use to make of them - doubtless the people who were agreeing with me at Fight Aging would be disgusted to know that I would be arguing strongly in favour of such therapies being made available free to all via our "socialised" health care system! I gather that's the position of Aubrey de Grey as well. Perhaps the reason some on the left are instinctively disquieted by this field of research is that they fear the post-breakthrough battle for 'longevity equality' would be lost, and I must admit that without a crystal ball there's no way of knowing for certain that's a baseless concern. But I don't see how it's a rational response to that fear to try to impede the research or wish it away - if it turns out increased lifespan is scientifically feasible, then we can be absolutely certain society will have to face up to the moral dilemmas posed by that reality sooner or later. Given the immense potential benefits for everyone, from my point of view it might as well be sooner.

Joan Bakewell's false choice on life extension

You might remember the post I wrote back in September after sending an email to Dr Aubrey de Grey, the controversial theoretician who claims there is a 50/50 chance that we will, within 25 years, achieve "longevity escape velocity", meaning that people who are alive and in a reasonably robust state at that point would be able to live on for centuries. I had queried the credibility of this 25-year timescale on the basis that it seemingly hadn't moved forward an inch in the seven years since it was first mentioned, and de Grey's research assistant Michael Rae wrote back to confirm that it was predicated on the assumption that there would be sufficient funding for research. This seemed to me a hopeless dream given the huge sums apparently needed, and it reinforced my suspicion that the chances of meeting the target date in the real world were more like zero than 50/50. Dr de Grey later left a comment here explaining that the position was essentially somewhere in between the two extremes, and that in his view significant progress had indeed been made in the last seven years - but roughly equivalent to the progress that would have been achieved over two years had full funding been available.

This whole field of research burst back into public view a few days ago with dramatic reports of the aging process being "reversed" in mice - claims that, ironically, de Grey and many others regard as being wildly overblown. But one upshot is that it's sparked off a flurry of debate about the potential consequences of the research, and one of the ten most-read articles on the BBC news website at the moment is a piece by Joan Bakewell suggesting that greater longevity may not be desirable. It's a superficially thoughtful commentary, but in truth it just runs through a series of standard knee-jerk reactions, most of which don't stand up to much scrutiny.

Firstly, there is the implicit assumption that any extra years of life are bound to be of extremely low quality, due to physical and mental frailty. But one thing that actually unites almost all scientists in this area - from the mainstream ones like S Jay Olshansky who seek to slow the aging process by a few years, to the "heretics" like de Grey who seek to conquer it entirely - is that they don't think an increased lifespan would be beneficial unless "healthspan" is boosted to an equivalent (or more likely greater) degree. There's always the danger of unintended consequences, of course, but there's no reason to fear the stated goal of the research.

Bakewell also raises the problem of overpopulation. This is, in principle, a fair objection, but when you stop to think about it, it also applies to just about every other medical advance in history. The eradication of smallpox boosted average human lifespan, and thus left us with a greater global population than we would otherwise have had - does that mean it was intrinsically undesirable? The principal objective of aging research is to head off the horrific diseases of old age, and therefore precisely the same cost/benefit analysis should be applied to it as to any other medical research - meaning, surely, that the potential benefits must be given precedence in the first instance.

Finally, there's the general sense in Bakewell's article that "a fuller life is better than a longer one". This is a superficially attractive philosophy, but once again, it looks somewhat different if you just tweak the implicit parameters a little. What if the "fuller life" lasted a mere twenty years, and the "longer life" lasted eighty? Would anyone seriously suggest that the fullness of the twenty years entirely makes up for the tragedy of the lost sixty years? Some might, but it would be a far tougher case to make, simply because of our perceptions of what a 'natural' lifespan is. And yet the span we fetishise as being optimal is just a random quirk of the stage of evolution we happen to be at - some species live much shorter lives than we do, other species much longer. If we do absolutely nothing, maximum human lifespan is likely to carry on gradually increasing of its own accord (global catastrophes permitting) - are we supposed to believe that process will be an 'unnatural' one, leading to a 'sub-optimal' outcome?

Mind you, if you're looking for a really over-the-top example of knee-jerk reactions, Bakewell is no match for this hysterical profile of the mild-mannered Dr Cynthia Kenyon at Mindfully.org -

"We sincerely hope that anything close to what Kenyon is looking for is ever (sic) found. Distinguished professor or not, this is an extremely myopic view of life on earth — to forget about those who already live an eternal life, albeit in damnation, to extend the lives of the rich who are able to afford such pseudo-science.

We hope that one day Kenyon and others with similar quests will see the futility in their actions. If they truly want to make a contribution to life on earth, then they should find a way to increase equality rather than searching for things that will undoubtedly increase inequality.

We will all be in a very troublesome situation if life is extended beyond what it already is."

Which begs the obvious question - if this really is 'futile pseudoscience' with no chance of succeeding, why the need to fret about such purely hypothetical horrors? It seems they doth protest a little too much. In any case, it's a transparently bogus argument to suggest that aging research is "at the expense" of improving the health of the world's most disadvantaged - they might as well say that funding for the arts or for astronomy is self-indulgent nonsense that is costing lives in Africa. It is actually possible - or at least it ought to be - to do more than one good thing at a time. Moreover, without a crystal ball, who can actually tell whether any anti-aging therapies that come along will be so prohibitively expensive that they will only be available to a wealthy elite? And even if that's the case for a transitional period, doesn't the same problem apply to many life-saving drugs at present? The idea that those drugs should never have been invented in the first place in case they temporarily increased inequality seems utterly risible.

All the same, Mindfully.org's display of doublethink neatly brings me full circle - my own question mark is not about the desirability of the goal, but rather its feasibility in anything close to the foreseeable future. Only time will tell.

Aubrey de Grey responds

For anyone who was interested in the piece I wrote a few weeks ago querying the timetable for potential therapies that might radically extend human lifespan, Dr Aubrey de Grey has left a reply :

"This is Dr. de Grey. Thanks to you both. All I would offer in my defence is that I do in fact insert "subject to funding" into my replies to questions on timeframes much more often than is apparent, but journalists just leave it out (rather as they insist on describing my goals as "immortality" and so on). My view is that progress in the past seven years or so since I started making these timeframe predictions probably amounts to about two years of the progress I think we would have made with full funding, so it's not as bad as all that."

Extending life - on an ever-expanding timetable?

If you happened to see the umpteenth repeat of BBC 4's (peculiar but rather good) comedy/science crossover show It's Only a Theory the other night, you'll have seen the unforgettable figure of the epically-bearded Dr Aubrey de Grey expounding his provocative proposition that the first 1000-year-old human being has probably already been born, due to supposedly imminent breakthroughs in regenerative medicine.  I think the first time I heard of de Grey was a number of years ago when he briefly appeared on an episode of Horizon about the prospects for expanding human lifespan.  I have to say - perhaps due to the way he was edited - he came across on that occasion as rather deranged, comparing the thousands of daily deaths from aging to 9/11, and angrily demanding that something be done to stop the "carnage".  So it was interesting to see him given the time to make his case in a much more measured and logical way.  He doesn't actually claim that the technology that might enable people to live for centuries is just around the corner, but he does suggest that it will be possible within a few decades to extend healthy lifespan by approximately thirty years, and - crucially - that this will buy enough time for further breakthroughs in rejuvenation techniques to be made, which in turn will buy yet more time, and so on.  He calls this process "longevity escape velocity", and it's upon this that he bases his conviction that people currently alive might go on to live unimaginably long lives.

I was sufficiently intrigued by all this a few months ago that I decided to read up on the general subject and see just how far to the fringe de Grey's views actually are within the scientific community.  The answer was slightly surprising.  While (as you might expect) his particular blueprint for the rapid conquest of aging is well beyond the bounds of mainstream thinking, there does seem to be a genuine sense that some kind of breakthrough is forthcoming, with leading experts talking confidently of a more modest seven year increase in healthy lifespan in the foreseeable future.  For the avoidance of doubt, this would not be achieved by the conventional means of tackling specific illnesses, but by genuinely contriving a way in which someone who is, say, chronologically 60 years old, could be biologically a few years younger than that.  So does this mean that the only difference between de Grey and the mainstream scientists is scale of ambition - seven years versus thirty?  Not quite.  There is in fact an almost total divergence of approach, with the majority of scientists in the field working more or less exclusively on the slowing of the aging process, while de Grey intends to reverse it.  His elaborate plan for achieving this ("Strategies for Engineered Negligible Senescence" or "SENS") is, his critics contend, nothing short of pseudo-science, as there is currently no firm evidential basis for believing it will work - in contrast to the possible methods for slowing aging, which have repeatedly shown their promise through laboratory tests on animals.  Dr de Grey counters that his is a goal-directed engineering approach, something which many curiosity-driven scientists simply cannot understand.  He cites as an example the Wright Brothers, who in the design and construction phase had no way of knowing for sure that their flying machine would work - but if they'd needed that certainty to proceed, they'd never have bothered trying to work towards their goal in the first place.

So it's a kind of theological dispute, but one that matters immensely, because the believers in each approach are in competition for funds and credibility.  Some - although not all - of the mainstream biogerontologists are furious with de Grey, believing his high-profile promotion of what they see as "quackery" is hindering their own chances of progress.  As a non-scientist, I'm clearly in no position to judge if they're right about the unscientific nature of de Grey's ideas, but having read some of his papers and interviews from the last few years, one very simple thing does repeatedly leap out and bug me.  He always seems to state exactly the same timescale for 'longevity escape velocity' - that there is a 50/50 chance of proof-of-concept in mice within ten years, and of the first therapies being available to humans within 25 years.  Clearly, with seven years or so having elapsed since he started making this claim, those numbers should have come down accordingly - instead, they have remained absolutely static.  With no real trace of an explanation for this, the claimed timescale does start to look suspiciously like a sleight-of-hand, solely designed to grab public attention.

Anyway, I'd heard that de Grey was reasonably approachable and might respond to emails, so a few weeks ago I decided to chance my arm and go to the horse's mouth with my concerns.  I think I was also slightly hoping I might get a rare Scot Goes Pop 'exclusive' out of it!  In the end one of his research assistants was kind enough to send me a long and detailed response which, while repeatedly slipping into sales patter, does to be fair address the points I had raised in a very full and frank way -

Hi James,
My name is Michael Rae; I'm one of Dr. de Grey's research assistants, and coauthor of his recent book, "Ending Aging"

(This is the new, paperback edition, which has an Afterword covering some of the advances in SENS science that were made after the publication of the hardcover).

With all of his duties in research, promoting engineering-based biotechnologies to arrest and reverse biological aging, and the promotion the book, Dr. de Grey has for some time been unable to keep up with most of his correspondence; when he received your email, he asked me to send his apologies, and answer your question as best I can.

You wrote:
> I've
> recently read a lot about your work on aging, and while I'm
> obviously not in a position to judge for myself the scientific
> plausibility of your ideas, there is one simple problem that leaps
> out at me (and I'm sure many others) about the credibility of your
> claims.
>
> In every article and interview I've seen going back to at least
> 2003, you've given exactly the same estimated timescale - a 50/50
> chance of robust mouse rejuvenation within ten years, and of the
> first therapies being available for humans within 25 years.  But if
> you'd been right about that in 2003, we should of course by now be
> just three years away from proof of concept in mice, and eighteen
> years away from the human breakthrough.
>
> Perhaps what you really mean is that there would be a 50/50 chance
> of meeting these ambitious timescales IF the $1 billion you need
> magically became available right now?

In fact, that's exactly what it means: we could well be as little as 25 years away from the goal *once we get started* . So far, unfortunately, the world has not begun to push for it. While SENS Foundation is doing the greatest amount of leveraged, critical-path work that we can on our limited research budget, and while most of the challenges that need to be tackled for achieving comprehensive rejuvenation are being funded and pursued to one degree or another by government and industry research, still there is nowhere near the level of intense, single-minded commitment worldwide required to achieve this goal.

> If so, that puts a completely
> different complexion on things, because - for better or worse - that
> scale of investment is surely not going to be forthcoming in
> anything close to the foreseeable future, and the chances of hitting
> those timescales in the real world is therefore not 50/50, but
> essentially zero.

Wow, and I thought I was a pessimist! But the idea that there is NO chance that this scale of investment could be forthcoming strikes even me as entirely unreasonable. The 2010 Haiti earthquake got commitments of US$3.3 bn to help out 3 million victims; the 2004 Indian Ocean tsunami  got commitments nearly twice that; and to use an hackneyed example, the TARP fund is catechismally invoked as the "$700 bn bailout."

Right now, there are 100,000 people dying of aging worldwide every single day, and many times this number needlessly sliding further down the progressive slide of age-related disease, disability, dependence, and dementia. $1 bn (or several times this) per year is a pittance, even within biomedical research: the NIH got US$$30.5B for FY. 2009, for goodness' sake!

But of course, that doesn't mean it's inevitable, or easy to mobilize. Surely you didn't think that Dr. de Grey was saying that we could all sit on our butts, and business-as-usual would give even odds of human rejuvenation in a quarter century.

> Or, if that's not the case, was there some other factor that was
> holding back the progress of research in 2003 or 2006 that doesn't
> apply now?

It still applies now: it's simply funding, and proactive refocusing of biomedical research and (soon thereafter) some regulatory tweaks.

> I suppose what I'm really asking is this : doesn't it
> seem overwhelmingly likely to you that in 2015 or 2020, you'll still
> be giving media interviews in which you're saying "we could be just
> ten years away from doing this in mice, and 25 years away in humans"?

Overwhelmingly, no -- but very possible in 2015, and plausible in 2020.

So what are you going to do about it >:) ?

If you're ready to help us to hasten progress in SENS science, we have quite a few listed here:

http://sens.org/help-us/volunteer

Also, you can pick up a copy of Aubrey's and my book (link above) and, after having read it for your own further understanding, get the word out by passing your copy around to others you know, and/or by donating it to a library, and/or by picking up extra copies for the latter 2 purposes.

Another one: have you checked out _Rejuvenation Research_ ("an international, interdisciplinary, peer-reviewed academic journal that covers all aspects of biology and biomedicine relevant to the combating, and ultimately the reversal, of age-related physiological and cognitive decline in nonhuman species and eventually in humans"), of which Dr. de Grey is Editor-in-Chief)? If you're a student or academic, and your institution has a subscription, you should be able to get direct online access -- and if it doesn't, you can recommend it here:

http://www.liebertpub.com/library.aspx?pub_id=127

This would not only give you access to the journal, but would help to disseminate its high-quality biogerontological research at your institution. You would need to get your library's contact info, preferably for the collections department; these are usually available on the 'contact' page, or one can ask a librarian about the right person to contact about a subscription recommendation.

And (naked plug!) remember that you can help to ensure that real age-reversing biotechnology becomes available as soon as possible, alleviating the most age-related suffering and death, by making a donation to support SENS research:

http://sens.org/donate

I leave it to you to choose how you will take on the moral and scientific challenge of biological aging. However you proceed: live long -- live young!

-Michael

So many thanks to Michael for taking the time to respond so thoroughly.  While he clearly genuinely feels there are more grounds for optimism on the funding front than I can conceive of, I do still think Dr de Grey should be fronting up about that crucial caveat to a much greater extent when speaking to the media.  And to address Michael's question (ie. did I really think de Grey was saying his 25-year timescale was in no way contingent on some fairly dramatic changes in thinking on the part of policy-makers) - well, whatever I may have thought, frankly I do believe that is the misleading impression he has been leaving his audience with on many occasions. As for my own "contribution", since I'm not actually a student, nor an academic, nor a millionaire, I think writing this post will probably have to do to be getting on with!

Lies, damned lies and...

This is a bit of a random post, but as "voodoo statistics" have been something of a recurring theme on this blog, I thought I'd draw attention to a textbook example of an area in which no-one seems to have the slightest clue which numbers are accurate or what they actually mean. A few weeks ago, there was a batch of stories about a possible method to slow down the aging process, and they all confidently asserted one central 'fact' - that, as things stand, an individual only has a one in 10,000 (0.01%) chance of living to 100. Those seemed startlingly long odds, given that most people probably know at least one person who's lived well into their 90s. But I just automatically assumed the figures must be authoritative - until, out of curiosity, I did a quick search engine check. It turned up these curiously contradictory nuggets of "information" -

According to the BBC, a baby boy has an 18.1% chance of living to 100, and a baby girl has a 23.5% chance.
BUT a 40-year-old man has only an 8% chance, and a 40-year-old woman has an 11.7% chance. (So the longer you live, the less chance you have?)

According to Thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com (catchy title) an individual has a 2% chance of making it to 100.

This American actuarial table seems to imply a 0.7% chance for men, and a 2.2% chance for women.

So what is the actual truth? Is there an actual truth? Answers on a postcard...

A fascism of statistics

Last night, in a lengthy programme on Channel 4, Rageh Omaar explored the highly controversial issue of whether there are innate differences between the levels of intelligence of different races. In each thread of his investigation, Omaar allowed the proponents of the most provocative theories to set out their case, before seeking to demolish their arguments. From my own perspective, he did so extremely convincingly, by showing that the genetic differences between races are too minimal to produce the dramatic differentials in intelligence that have been suggested, and by pointing to the 'Flynn Effect', which could imply that IQ tests are less of a direct measure of intelligence, and more a measure of an individual or group's "adaptation to modernity". However, as the programme progressed, I could just imagine the self-anointed experts on the field of IQ (many of them statisticians) saying "this is proving nothing, he's missed the point entirely, anyone who thinks that IQ tests do not directly and accurately measure intelligence simply does not understand statistics".

And that, I think, is the essence of the whole problem with the debate over the validity of IQ tests, regardless of whether it relates to race, or merely the 'classification' of individuals by intelligence. There's a kind of 'statistical fascism' at play, whereby the statisticians refuse to seriously engage with any of the powerful counter-arguments to the prevailing wisdom that IQ tests are meaningful measures of intelligence - unless it is done on their own terms, with detailed reference to 'meta-analyses' and 'regressions' and all sorts of other incomprehensible language. Given the huge importance of this subject to everyone, it simply can't be right that authoritative discussion of it is restricted to such a narrow area. For one thing, anyone who has ever taken an IQ test (I've taken the American SAT, which in its old form closely resembled an IQ test) won't need a grounding in statistical theory to intuitively understand that it simply can't be a pure measure of intelligence - your score will also be significantly affected by your level of motivation to do well, your composure under severe pressure of time, etc, etc. The statisticians would respond by pointing out that, if an individual takes several different IQ tests, the outcome will typically be remarkably close every time. But this doesn't really address the point - if someone's composure and motivation levels remain fairly constant every time they take the test, it follows that the scores would remain constant as well. This constancy does not constitute proof that IQ tests accurately measure intelligence.

Ah, the statisticians might respond, you're overlooking the high level of correlation between IQ scores and success in life, as measured by educational attainment and income levels. But doesn't an individual's composure under pressure and motivation to succeed also play a significant role in determining their life chances? If an IQ test is partly measuring those things, it's hardly surprising there would be such a correlation.

In fact the buzz phrase of statisticians in this field appears to be "intelligence tests are the most accurate of all psychological tests". Just goes to show how ropey all the others must be.