Risk and rationality

I had the privilege of attending the 2016 Australian Academy of Science Theo Murphy High Flyers Think Tank in Canberra just recently. I’d only heard about it via a single tweet the day before applications were due, but with the topic of “An interdisciplinary approach to living in a risky world”, my response was: yes please.

We were also asked to choose our preferred topic for breakout-group discussion, and I got my obvious favourite, the technical theme of “Uncertainty, ignorance and partial knowledge”, which turned out to have some focus on decision theory. The session would chaired by Prof. Mark Colyvan, a professor of Philosophy at my alma mater, The University of Sydney, who had recently responded to Luke Barnes’s recent fine-tuning of the universe talk. Some of the recommended reading got me thinking about matters we didn’t get to cover (like how much I don’t like maximin), but I’ll discuss with Mark, and I’m sure I’ll blog about that later. In the meantime, our breakout group spent a couple of hours throwing around our thoughts and ideas and have begun to craft a report and recommendations for the Academy regarding decision-making and risk communication in the face of uncertainty.

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Wrap up from chair Prof Hugh Possingham

My fellow delegates were such interesting people from diverse backgrounds like health, maths, stats, philosophy, history, law, geology, ecology, microbiology etc, and absorbing ideas from these amazing people over the two days provided a complete mental recharge. It was like NYSF for grown-ups. Even the conference dinner speech by emergency doctor David Caldicott was so stimulating, leaving my laughing and crying, I’d dare say it was the “best event speech ever”.

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Slide from Prof Terry Speed’s talk at the AAS Think Tank

Actually one of the things I most enjoyed at the Think Tank was finding out people’s thoughts on rationality during tea break, as always. As it turns out, most people I spoke to (about this topic, sample size ~5) were adamant that people are at heart, irrational creatures. Only one person (besides myself) thought otherwise. I’ve been told I have to read Daniel Kahneman’s Thinking Fast and Slow to hear more arguments against the assumption of rationality. Apparently there are tests for this sort of thing…

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Outliers are people too

I confess: I like Tom Stoppard because his plays highlight all the intellectually stimulating but somewhat pretentious (aren’t they all?) discussions I’ve had over the last 15 years. His latest, The Hard Problem, was no different. It follows Hilary, a psychology student who we meet as she applies for a job at the Krohl Institute for Brain Science, hoping to inject some humanity into their research. As always, Stoppard treats us to some witty banter, this time about altruism, animal behaviour, coincidence, consciousness, ego, evolutionary biology, morality, neuroscience, religion, and the worlds of academia and finance. The Hard Problem is perhaps less clever and fresh than Arcadia or RosenGuild, but fun and thought-provoking nonetheless. Some of the characters are true to the bone while others, disappointingly, feel typecast, but there is definitely some familiar truth in all. Overall, I’m pretty happy with the brain-lit Hytner production that we saw streamed live from the National Theatre in London – worth seeing.

Parth Thakerar (Amal), Vera Chok (Bo), Lucy Robinson (Ursula), Rosie Hilal (Julia), Olivia Vinall (Hilary) and Damien Molony (Spike) in The Hard Problem by Tom Stoppard @ Dorfman, National Theatre. (Opening 28-01-15) ©Tristram Kenton

Parth Thakerar (Amal), Vera Chok (Bo), Lucy Robinson (Ursula), Rosie Hilal (Julia), Olivia Vinall (Hilary) and Damien Molony (Spike) in The Hard Problem by Tom Stoppard @ Dorfman, National Theatre.
(Opening 28-01-15)
©Tristram Kenton

Rational Agents

Recently I attended the second ever Bayesian Young Statisticians’ Meeting (BAYSM`14) in Vienna, which was a really stimulating experience, and something pretty new for me, being my first non-astronomy conference. I won a prize for my talk too, which was pretty sweet!

BAYSM`14 venue

Swanky BAYSM`14 venue at WU Vienna designed by architect Zaha Hadid

During the two-day overview of theory and a variety of applications by the newest people in the field (read about the highlights over at the blogs of Ewan Cameron and Christian Robert), we heard from a few Keynote Speakers including Chris Holmes. In his talk, he mentioned the world of rational decision makers as envisioned by Leonard J. Savage in his 1954/1972 tome The Foundations of Statistics (adding that on my ‘to read’ list), and went on to describe the application of a loss function and minimax to avoid worst-case scenarios. Minimax isn’t the only approach to decision-making; I think other approaches  are more relevant to our behaviour, as I’ll describe later.

“If you lived your life according to minimax, you’d never get out of bed” – C. Holmes

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Free Candy

In my fist was a single piece of candy wrapped in bright yellow cellophane, accompanied by an overwhelming feeling of guilt and sadness. I had just seen a little boy grab four: one for him, one each for mum and dad, and one for grandma, presumably back at home. There was a sign on the wall saying “Please Take One”, but it still didn’t feel right.

“We shouldn’t do this. Don’t you see? We’re killing him.”

“Untitled (Portrait of Ross in L.A.)”

“Untitled (Portrait of Ross in L.A.)”, Félix González-Torres, 1991. Multicolored candies, individually wrapped in cellophane; ideal weight 175 lb.; installed dimensions variable, approximately 92 x 92 x 92 cm (36 x 36 x 36 in.)

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We are all made of stats

Children are very good at science. They start with broad priors (anything is possible) and learn through collecting data (see picture below) what conclusions are supported best by the evidence. They experiment, make mistakes, and test the variations on a theme. They learn what is dangerous; they learn what is tasty; they learn how to speak.

Kids doing science

Kids doing science

Our responses to experiences are very similar to Bayesian reasoning. Take trust as an example. If some dudette off the street – let’s call her Margaret – were to recommend a movie, say Moon, we might not heed her words since we have no reason to think we’d have the same taste in movies as her, but if upon watching Moon we found that we quite enjoyed it – we’d be more likely to rely on Margaret’s next tip, say Wadjda. And if Wadjda was also to our liking, we’d probably trust Margaret’s advice when she suggests Fast & Furious 6 (oops). But that blunder would reduce our confidence in her next recommendation, etc. If we define our experience of the movie in binary terms such as “liked” and “disliked”, the situation resembles the classic coin-toss experiment in which one tries to determine if a coin is biased by flipping it many times.
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Truth, Beauty and a Picture of You

recent interview with George Ellis, from the University of Cape Town, had him confront the potential for his religious faith to affect his scientific views. (Part of) his response:

“Many key aspects of life (such as ethics: what is good and what is bad, and aesthetics: what is beautiful and what is ugly) lie outside the domain of scientific inquiry”

appears – at first glance – to concur with Stephen Jay Gould’s vision of non-overlapping magisteria (NOMA). NOMA demands that moral values lie in the domain of religion, a claim heavily criticised by Richard Dawkins in his book, The God Delusion. Not a huge fan of the book, but I’m definitely less of a fan of NOMA. For completeness, according to NOMA, art and beauty then belong to yet another “magisterium”. Ellis argues, rather, that ethics “what is good or bad” is “a philosophical or religious question”. [Edit: to clarify, my qualms are regarding whether this is a religious question, not whether it’s a philosophical question.]

“Scuola di Atene”/“The School of Athens” Raphael

“Scuola di Atene” or “The School of Athens”, fresco by Raphael 1509-1510

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Correcting for the Selection Function: Gender

The under-representation of women and minorities within certain areas of academia, business and education, particularly in high-paying jobs and managerial roles is well documented. Anti-discrimination laws can only do so much when unconscious bias is rife. This is where affirmative action comes in, controversial as it is, in the form of any of the following:

  • scholarships for minorities
  • prioritising minorities given equal qualifications
  • diversity quotas.

The general idea is to account for the “selection function” that is privilege. In science, data is collected from objects which satisfy certain criteria. Often, the data we really want is convolved with the selection function. An example from astronomy is when you include only galaxy clusters brighter than a certain threshold in your sample; you are more likely to include objects: of higher mass; at low-medium redshift; that have cool-cores. If one wants to know the properties of an otherwise “fair” sample, you must perform some kind of deconvolution or correction (easier said than done). That’s what affirmative action attempts to do (also easier said than done). For the rest of this blog-post, I look at recent attempts to improve the representation of women, in particular, as well as responses to these .

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