Why the tails come apart

January 16, 2015 § Leave a comment

Many outcomes of interest have pretty good predictors. It seems that height correlates to performance in basketball (the average height in the NBA is around 6’7″). Faster serves in tennis improve one’s likelihood of winning. IQ scores are known to predict a slew of factors, from income, to chance of being imprisoned, to lifespan.

What’s interesting is what happens to these relationships ‘out on the tail’: extreme outliers of a given predictor are seldom similarly extreme outliers on the outcome it predicts, and vice versa. Although 6’7″ is very tall, it lies within a couple of standard deviations of the median US adult male height – there are many thousands of US men taller than the average NBA player, yet are not in the NBA. Although elite tennis players have very fast serves, if you look at the players serving the fastest serves ever recorded, they aren’t the very best players of their time. It is harder to look at the IQ case due to test ceilings, but again there seems to be some divergence near the top: the very highest earners tend to be very smart, but their intelligence is not in step with their income (their cognitive ability is around +3 to +4 SD above the mean, yet their wealth is much higher than this).[ref]Given income isn’t normally distributed, using SDs might be misleading. But non-parametric ranking to get a similar picture: if Bill Gates is ~+4SD in intelligence, despite being the richest man in america, he is ‘merely’ in the smartest tens of thousands. Looking the other way, one might look at the generally modest achievements of people in high-IQ societies, but there are worries about adverse selection.[/ref]

The trend seems to be that even when two factors are correlated, their tails diverge: the fastest servers are good tennis players, but not the very best (and the very best players serve fast, but not the very fastest); the very richest tend to be smart, but not the very smartest (and vice versa). Why? « Read the rest of this entry »

Why vegetarianism is obligatory

January 16, 2015 § Leave a comment


(Written a few years ago now…)

How good were the ancient greats?

January 16, 2015 § Leave a comment

Summary: In many fields, the ‘greatest’ (be they philosophers, playwrights, composers, etc.) are selected disproportionately more from those who lived in the distant past. I speculate as to what might be driving this bias towards ‘ancient greatness’, but one important takeaway is that we can be confident that the greatest of the past are likely inferior to the greatest amongst us today in terms of ‘innate ability’. So perhaps we should not regard them so highly.

[Very rough draft: advice/criticism on data, analysis, or style welcome, as is advice on whether this is worthy of going into academia, and if so how. Thanks to Rob Wiblin, Will Crouch, Catriona McKay, and Sam Bankman-Fried for ideas/prior discussion.]


If you look at a field of human endeavour (mathematics, philosophy, the arts, military strategy – pretty much anything) the reputedly ‘greatest ever’ in these fields have tended to live in the distant past.
Take philosophy as an example. Polls of the ‘greatest philosopher’ of all time broadly agree on a corpus of ‘ancient greats’. Here’s the top ten from a poll from Brian Leiter’s philosophy blog, with their dates added:

  1. Plato (428-348 BC)
  2. Aristotle (384-322 BC)
  3. Kant (1724-1804)
  4. Hume (1711-1776)
  5. Descartes (1596-1650)
  6. Socrates (469-399 BC)
  7. Wittgenstein (1889-1951)
  8. Locke (1632-1704)
  9. Frege (1848-1925)
  10. Aquinas (1225-1274)

The list is dominated by ancient Greeks and enlightenment Europeans, with only a couple of thinkers in the last couple of centuries getting a look in. I think Leiter’s poll (modulo some quibbles with the exact ordering) broadly captures the consensus view amongst who are the greatest philosophers, at least in the western tradition.

On the face of it, having the ‘greatest ever’ philosophers spread out from antiquity to the present day seems plausible. But consider how the human population has grown over time (data from Wikipedia):


The population has grown dramatically, so if we think about birth order rather than time, the greatest philosophers were generally among those born first. Why? « Read the rest of this entry »

Off duty

January 16, 2015 § Leave a comment

“Hi, single to the hospital, please.”

“You’re not ill, are ya?” The bus driver teased.

“No-no, I’m just training there.”

He let her go with a laugh and she walked up the aisle of the bus. The white tunic with blue trim poking out from under her coat made me guess student nurse. I was next in the queue; the driver spared me the same joke when I asked for the same ticket. « Read the rest of this entry »


January 16, 2015 § Leave a comment

I am now a doctor. The result that I passed my finals came on Friday, and the declaration happened Sunday afternoon. I start work as the most junior of junior doctors – a Foundation Year 1 – at the end of July in Milton Keynes. So now you know where to avoid if you get sick in August.

Traditionally (at least in the ‘States) students have a valedictory address at the end of their course, given by the top-ranked student of the year. This is a less auspicious farewell: I am a long way down any order of merit you care to name, and medical school has been a struggle. Things did get better in my final year, but the last six years haven’t been some Bildungsroman of how I transformed from spotty student to modern medical professional.

I’m still scared I’m not good enough. From what I haven’t done (at least, not on a non-plastic patient), from what I don’t know, to when I haven’t listened, there are fertile grounds for doubts. I find my mind keeps racing from these defects to hypothetical disaster. Although the medical profession is sane enough to carefully circumscribe the responsibility of junior doctors like me, this is still much more than I ever had as a student, and the excuses (“sorry, just a student, I’ll go and get a doctor”; “I can learn that later, I’m not qualified yet”) are gone. I feel like I am playing catch-up to the doctor I want to be, and I haven’t even started. « Read the rest of this entry »

Unfriendly AI cannot be the Great Filter

January 16, 2015 § Leave a comment

Summary: The fact we do not observe (and have not been wiped out by) an UFAI suggests the main component of the ‘great filter’ cannot be civilizations like ours being wiped out by UFAI. Gentle introduction (assuming no knowledge) and links to much better discussion below.


The Great Filter is the idea that although there is lots of matter, we observe no “expanding, lasting life”, like space-faring intelligences. So there is some filter through which almost all matter gets stuck before becoming expanding, lasting life. One question for those interested in the future of humankind is whether we have already ‘passed’ the bulk of the filter, or does it still lie ahead? For example, is it very unlikely matter will be able to form self-replicating units, but once it clears that hurdle becoming intelligent and going across the stars is highly likely; or is it getting to a humankind level of development is not that unlikely, but very few of those civilizations progress to expanding across the stars. If the latter, that motivates a concern for working out what the forthcoming filter(s) are, and trying to get past them. « Read the rest of this entry »

Why people who boast about their IQ are losers

January 16, 2015 § Leave a comment

I have no idea [what my IQ is]. People who boast about their IQ are losers – Stephen Hawking

A quick and dirty signalling explanation as to why Hawking is right: « Read the rest of this entry »

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