Irrational decision-making as evolutionary survival

One of the key fallacies of orthodox economics is that people are rational decision-makers with perfect information.

We can knock "perfect information" in so many ways, but a recent New Scientist article* reminded me how irrational we are, too.

Inter alia, the article points out something quite meaningful: that we have "a brain shaped by natural selection to see us through this messy world".

Think about that.  Although survival-wise it helps to be capable of rational thought (and all that goes with it, such as thinking ahead, concept-of-self, etc), that doesn't ipso facto mean that our brains evolved in the unitary direction of rationality only.  That's a very good explanation for an awful lot of human foibles.



Some examples of decision-making factors we probably inherit in an evolutionary sense are: existing biases, emotions, expectations, co-operation and conformity (sometimes you just follow the herd).  Altruism too: the article suggests that the consequent feel-good is "evolution's reward to team players".

A good example of irrationality in decisionmaking: discounting the future: the strong preference for small gains in the present over large gains in the more distant future.  This is a great factor in the sub-optimal global response to environmental threats.

Some of the not-entirely-rational mechanisms mentioned by the article include:

- confirmation bias: our propensity to be taken in by something that confirms our pre-existing biases;
 - loss aversion: it feels worse to lose something small than to risk it to gain something large;
 - the anchoring effect: basing decisions in novel situations on random, loose, or irrelevant connections;
 - the sunk-cose fallacy: deciding whether to continue [expending resources] on the basis of what's already been put in it (a common trap for many investors and poker players alike);
 - inconsistent preferences: preferring a over b, b over c, but c over a.

For the last one, it is suggested that we are likely to be making choices based on several different factors that may be decided by different areas of the brain, so ultimately "your preference will depend on the region that dominates at the time" - that is, when you are faced with such a binary decision.

At various times, these "tricks" can all be seen as useful survival mechanisms - and sometimes this means survival in a group sense rather than individual.

so it's noto necessarily a problem: it's just that as individuals we're not as rational as we'd like to think.

And the article says we face between 2,500 and 10,000 decisions every day.  Daunting, if we didn't use short cuts.

*"Making Your Mind Up" by Kate Douglas in the 12 November 2011 issue.  Oh all right, it's not recent, but I'm a bit behind, and I only just unsealed it recently.

Brain Pruning: the answer to autism?

"In adults [the human brain] has perhaps 100 billion neurons, each connected to its neighbours by 5000 synapses or so." New Scientist, 1 October 2008

"In the f[o]etal brain, all parts of the brain are interconnected, but as we age, the connections are pruned.  If the pruning genes get it wrong, the connections are off." - according to Vilayanur S Ramachandran, in New Scientist, 8 January 2011 (The fastest brain in the west, p26)

There is no disputing that the human brain undergoes a pruning process whereby the synapses, the connections between neurons, are culled while the brain is developing.

This is a normal part of the development process: meaningful connections are retained, and [at least some] unused ones are discarded.  This is a rationalisation that begins before the baby is born and continues for years afterwards.

And it's those synapses that enable brain functionality, particularly connections between different areas, which facilitate all manner of associative thought and reasoning.


The second quote above was made in the context of neuroscientist Ramachandran's study of synaesthesia, the leaking of one sense into another (the most common example being seeing letters or numbers as specific colours).

Occam's razor says to me that it need not take Ramachandran's concept of "pruning genes" for the pruning process to go awry. Development both before and after birth are affected by quite a range of factors.

Yet it struck me that disruption to that process may account for high-functioning autistics [so called "savants"] in particular.  The ability of Daniel Tammet, for example, to recall thousands of digits by visualising the string as a rolling landscape - that sounds like abnormal connections remaining in place between disparate parts of the brain.

Incorrect pruning may account for autism in a wider sense - not just those that are high functioning - but it seems easier to look to that process when describing aberrantly strong functionality than a weakening of capability, which can be due to a much wider variety of factors.

Why IQ tests don't work

We've all heard people decrying the value of IQ tests: particularly that they are either culturally biased, or that they only exhibit one dimension of intelligence.

I suggest additional reasons for that value being limited.


I have always found IQ tests relatively easy - but I'm mathematically inclined.  Further, in my experience people that are clearly below an IQ of, say, 80, are clearly lacking some general capabilities.

My thinking is that  the upper end of IQ results reflect mathmatical/logical capability, but it doesn't measure the broad range of human capabilities.  Likewise, low scores are indicative of a disability.  Yet for those who score mid-range, it's hard to say anything useful about their intelligence.

There have been a number of alternatives suggested for the straight IQ measure, such as intelligence that is social, emotional, visual/artistic, musical, and so on.  I find myself in agreement that "IQ" measures only a limited range of a person's intellectual capabilities.

My suggestion is that those IQ measures that score mid-range are only demonstrating their mid-range logic capabilities, and that we have no sufficient measure of their capabilites in the broader aspects of human capabilities.

It was suggested to me that those with aptitude for classical music are likely to be pretty intelligent on typical IQ measures.  Yet my reading of the music industry more generally suggests that there are many musicians that are neither very logical in general, nor very capable of managing their own lives - even equalising for other factors such as self-medication.  Syd Barrett is typically held up for this measure in the music sphere; Van Gogh - and many others - are rightly or wrongly depicted as exemplary in the musical world.  I would be surprised if surrogate IQ tests didn't place them mid-range; however, I'm sure there are vast swathes of musicians that are highly intelligence in the IQ measure - it's just that such a measure is not directly relevant to their  particular expertise.

[What it has to do with brain function is an interesting question.  Recent findings have, for example, suggested that autism is much to do with a differential ability (or dis-)  of different regions of the brain to communicate with each other - and that high-functioning autism (so-called savant) may be an aspect of the same, that is, abnormality in the networking of different regions of the brain.]


Comments welcome.

Tip of your tongue?

One of the things that keeps my mind active is the daily Target puzzle:

E T A
A B D
R M O

Try form words of four or more letters from the given ones above (no proper nouns or plurals ending in S). Today's target: "29 words, good; 43 very good; 57 excellent" - that is, try to get half, three quarters, or all the words they identify from their dictionary (Chambers).

Of course, they miss a few words that aren't in Chambers, but for some reason they sometimes miss some common words.

I usually get the nine-letter word - but not always. Sometimes it comes to me as soon as I look at the set of letters; sometimes I work out a few of the smaller words, and it emerges from there. Sometimes, of course, I go for obvious prefixes, suffixes, or compound words.

But sometimes I have to actively stop seeking. I can't get it, so I move on to something else. Then I look back at it, and it can come to me immediately.

We've all had experience of that - and it's been confirmed as a specific neurological phenomenon, according to a letter published in New Scientist. It refers to a 2003 article in an American journal of cognitive psychology, the Psychonomic Bulletin and Review (specifically, v10 p730 - full paper here).

Well, that's not quite neurology. But they describe the conscious mind activating a wrong pathway, and that pathway being cemented in the mind, over-riding the pathway to the correct answer. Only when that process subsides can the pathway to the correct answer be activated.

Another correspondent notes that as an engineer, he encounters this so often that he deliberately sets himself design problems before he goes to sleep, and very frequently wakes up with the answer before him. He ascribes this more specifically to the amount of clutter inhabiting older peoples' minds. There is a strong inference that younger people are more likely to immediately either know the answer or not.

The brain and background problem-solving

How the brain works remains a fascination for me. Two of the tales that stay in my mind over the last few years are:
- the man with severe brain degeneration who simply experienced a certain loss of complex functionality - because he did exercise his brain well (mentioned here);
- Daniel Tammet, autistic savant who can memorise long strings of numbers - and perform complex calculations - by visualising them as shapes. (Discussed here.)

The one spoke to the capacity of the brain to rewire; the other possibly illustrated what can be achieved when the brain is rewired - or short-circuited - in some way.

Today's thought is somewhat more trivial, but an interesting question about how the brain works.

One good way to exercise the brain is with regular puzzles. A common one in daily newspapers is Target. Today, your goals range from 12 to 18 to 24 words in the following letters:

E I L
T B U
L N E

- but all words need to be at least four letters, include the middle letter, and you need to find the nine-letter word.

I can usually get between the middle and the top target, beyond which point the words can become arbitrary - dependent on the dictionary used.

Today I tried to work out the nine-letter word, but I just couldn't get it. I walked away, but in the next 30 seconds it just came to me.

This has happened from time to time, and so is not a coincidence. Is it something to do with the ability of the "subconscious mind" to keep processing in the background - and then feed the results to the "conscious mind"? Is it something to do with the forced foreground train of thought, which needs to be relaxed to allow the processing to better happen?

Thoughts welcome.

Answer (to the nine-letter word) tomorrow.

Some insights into mental illness

An article in the latest New Scientist gave some really new and fresh perspectives on mental illness, especially bipolar disorder, schizophrenia, and paranoid delusion.

I'll briefly summarise the insights that struck me as meaningful.

There is a main difference between schizophrenia and bipolar disorder: the apparent lack of emotion in the former, and extremes in the latter. However, it's unsurprising there's some conflation of the two: in reality, there can be considerable overlap.
Although there has been some effort to identify a genetic basis for these, nothing significant has been found so far...

On to paranoid psychosis. This can include delusions of persecution and grandeur, and auditory hallucinations. In fact studies have shown that about 10% of the population will experience those "voices"at some point in their lives. Research has linked these voices to inner speech, or verbal thought, as when children learn to think in words by talking aloud to themselves.

Patients have been shown to subvocalise when “hearing voices”, suggesting they can’t distinguish between their own thoughts and external stimulus.

Trauma has also been linked to paranoia. For instance, two studies have shown a high rate of sexual abuse in patients who hear voices.
There is also evidence that delusions follow long-term experiences of persecution, perhaps leading to oversensitivity. Further, persecutory people have been shown to form conclusions (often wrong) more quickly than average people. [perhaps that reflects higher stress levels due to trauma.]

Delusional people often experience difficulty understanding others’ feelings and beliefs.

All these factors can combine to produce full-blown paranoia.

Much of this may sound rather obvious [in hindsight], but it serves to demystify the illnesses.

The article mentions an interesting experiment involving two jars of beads, one with mostly red (over white) and the other with mostly white. Lay out a sequence from one jar, and ask a subject to decide which jar the beads came from. My thought: it may be helpful to demonstrate to patients the quicker rate of decision making than average, and the greater propensity to incorrect choices.

Cognitive behaviour is also canvassed in the article. An example of this is to encourage a patient to gather concrete evidence of their beliefs, then use experimentation to test that evidence.

The article concludes that these insights pave the way for a greater range of options in treating people with these illnesses.