Skip to main content

The Hidden Half - Michael Blastland *****

Michael Blastland is co-author of one of my favourite titles on the use and misuse of numbers, The Tiger that Isn't - so I was excited to see this book and wasn't disappointed.

Blastland opens with the story of a parthenogenic crustacean that seems to demonstrate that, despite having near-identical nature and nurture, a collection of the animals vary hugely in size, length of life and practically every other measure. This is used to introduce us to the idea that our science deals effectively with the easy bit, the 'half' that is accessible, but that in many circumstances there is a hidden half that comprises a whole range of very small factors which collectively can have a huge impact, but which are pretty much impossible to predict or account for. (I put 'half' in inverted commas as it might be fairer to say 'part' - there's no suggestion that this is exactly 50:50.)

We go on to discover this hidden half turning up in all kinds of applications of science and maths from economics to healthcare, from the lives of individuals who were delinquent as children to measuring the benefit (or not) of giving a poor family a cow. Blastland picks out a number of factors that tend to mislead us - that as humans we aren't consistent in our responses, that things change with location and time, that the way research is undertaken can generate false results, that principles can mislead us and far more. As he points out, what this does is make us aware of the limitations of applied maths (particularly economics) and science. He is not saying we shouldn't use them - they are far better than the alternatives - but we have to be aware of their limitations.

At the end of the book, Blastland comes up with some suggestions for dealing with the hidden half. It isn't going to go away, and there are no easy solutions, but he does have some interesting ideas on mitigation. For example, he suggests we should experiment more (with political policies, for example), remember that we are betting on knowledge rather than making use of certainty and, for me, most importantly that scientists, journalists and politicians should do more to communicate the uncertainty involved. It's not that we want our politicians to be hesitant, but it would be far better if they made it clear that there are very few clear linkages between policies and outcomes. I was particularly struck by some data on GDP figures. The media and politicians often spend ages agonising over a GDP change of, say 0.2 per cent. The headline figures are revised over time as better data is available: Blastland points out that a typical correction might be 0.4 per cent up or down (and can be as high as 1 per cent). This makes it very clear that making pronouncements based on a 0.2 per cent change is futile and highly misleading.

My only criticism is that I felt that the book could have done with even more specific examples: in this kind of book, it's the examples that have the real bite and savour. Blastland spends a bit too long philosophising on the hidden half in a way that feels a little repetitive. It's not there aren't great examples (plenty more than the ones mentioned above), it was just for me that the ratio of examples to musings wasn't quite right. A brief mention also to the cover design - it's very clever (though I couldn't help thinking it had been put on wrong and wanting to re-position it).

We are getting more books now about the reality of applied maths (particularly economics) and science, which is an extremely good thing, provided the message is carried through to journalists and others who have to communicate these matters to the public. An excellent book.
Hardback 

Kindle 
Using these links earns us commission at no cost to you
Review by Brian Clegg

Comments

Popular posts from this blog

The Infinity Machine - Sebastian Mallaby ****

It's very quickly clear that Sebastian Mallaby is a huge Demis Hassabis fan - writing about the only child prodigy and teen genius ever who was also a nice, rounded personality. After a few chapters, though, things settle down (I'm reminded of Douglas Adams' description of the Hitchhiker's Guide to the Galaxy ) and we get a good, solid trip through the journey that gave us DeepMind, their AlphaGo and AlphaFold programs, the sudden explosion of competition on the AI front and thoughts on artificial general intelligence. Although Mallaby does occasionally still go into fan mode - reading this you would think that AlphaFold had successfully perfectly predicted the structure of every protein, where it is usually not sufficiently accurate for its results to have direct practical application - we get a real feel for the way this relatively unusual company was swiftly and successfully developed away from Silicon Valley. It's readable and gives an important understanding of...

In Seach of Sea Dragons - Matthew Myerscough ****

It's common advice to would-be authors of narrative non-fiction to open with something dramatic - Matthew Myerscough certainly does this with the story of his being trapped under an avalanche on Snowdon (while his girlfriend, also carried away remains on top of the snow unhurt). It certainly is dramatic, but seemed entirely disconnected from the reason I got the book, which was to read about fossil collecting.  Luckily, though, in the second chapter we get into a more conventional 'how I got interested in fossils as a boy'. Having recently reviewed Patrick Moore's autobiography and noting that astronomy was one of the few sciences where amateurs can still make a contribution, it came to mind that palaeontology is another - Myerscough is a civil engineer by trade, but just as amateur astronomers can find new details in the skies, so amateur fossil hunters have been searching for these relics for centuries. When I give talks in junior schools, the two topics that guarant...

Robot-Proof - Vivienne Ming ****

As Vivienne Ming makes apparent, there seem largely to be two views of AI's pros and cons, both of which are almost certainly wrong. It's either doom-saying 'It'll destroy life as we know it' or Pollyanna-ish 'It'll do all the boring work and we can all be wonderfully creative and live lives of leisure.' Instead, Ming gives us a clear analysis of the likely trajectory for the workplace, particularly for the IT industry. She describes three 'equally flawed, intellectually lazy strategies' to deal with the impact of AI. The first is substitution and deprofessionalisation, using AI to allow cheaper 'AI-augmented technicians' to replace more expensive professionals, producing more low wage jobs and fewer mid-range. This does save money but leaves a company at risk of being easily outcompeted. The second is what Ming describes as the '"A-Player" Hunger Games', the approach favoured by Silicon Valley. This sees the growing rif...