Hard wired 17: Bias

In this post we’ll consider three of the most widespread (and misleading) of our evolved mental modules. We’ll look at ‘selective abstraction‘, ‘arbitrary inference’ and ‘confirmation bias’. Each of these is related in its own way to pattern recognition as described in part 16.

What’s most interesting from an evolutionary perspective is that these three aspects of human psychology, although universal, may not be advantageous in themselves. They may, in fact, be no more than evolutionary by products of pattern recognition.

There are many examples of by products, both physical and psychological. Certain genes seem to confer a variety of traits as though some evolutionary advantages cannot exist without other less positive or neutral correlates. The trade off between sickle cell anemia and protection from malaria discussed in part 9 is an excellent example. Evolution isn’t perfect and so neither is the human body – or the human mind.


Ornately carved spandrels

Sometimes these extra ‘add on’ characteristics can fool us. They look like the evolved characteristic that was favoured by natural selection but they’re not – they’re just the baggage that comes along with it. They’re what Stephen Jay Gould described as evolutionary ‘spandrels’.

‘Spandrels’ are the triangular blank spaces we see at the top of arches. They serve no structural purpose but in an arched building, a cathedral for example, they are inevitable by products of construction. However some spandrels, structurally useless by products or not, are so finely decorated that it’s easy to convince ourselves that they were the builders’ main focus and not the arch. So it is with evolutionary spandrels. They’re purely coincidental but they have the appearance of selected traits.

The tendency to see patterns and to concentrate only upon what is relevant has real advantages. Work on expertise and efficiency shows us the need to weed out irrelevancies from attention but along with that undeniably helpful tendency we find a few ‘spandrels’. As we consider these three ‘less than helpful’ psychological traits it will be helpful to remember that ‘evolved’ doesn’t necessarily mean ‘inevitable’. It does seem to be possible to resist these traits, however hard-wired they may be. As ever, knowledge is power.

Selective abstraction


Which pattern is most relevant?

As we know, experts and other, efficient problem-solvers develop a consistent ability to see relevant patterns without being distracted by irrelevancies. For most of us though there seems to be an equally consistent problem, at least until we gain experience in understanding just what is and is not relevant. We tend to focus as much upon irrelevancies as we do upon the relevant.

Experts rely upon experience to recognise which aspects of the current situation are relevant. They use memory of previous events to find meaningful patterns in the present. They notice similarities and take action accordingly. As do we all.

The problem comes when non-experts (that means all of us most of the time) try to identify meaningful patterns. We tend to notice what fits our existing assumptions and worldview. We also tend to ignore or under-emphasise any information that doesn’t fit. In short we selectively abstract the evidence that we already agree with and filter out everything else.


Abu Qatada

This means that whatever we first believe tends to stick (even if it’s wrong). That’s why no amount of contrary evidence will dissuade the racist, the religious extremist or the political zealot from their chosen opinion. They literally discount all the information that doesn’t support their preconceptions. It’s also why humans are so easy to manipulate. All the manipulator has to do is set up a worldview and we do the rest.

Psychological priming is a common sales and persuasion trick. Prime the prospect to think of a certain price range so that whatever is offered is seen through that particular lens.

In politics priming is just as easy. For example the current UK government has successfully primed much of the population to believe that disabled people are ‘scroungers’ and that unemployed people are lazy. Neither of these assertions are objectively true but that doesn’t matter. Selective abstraction means that these ideas are difficult to shake.


David Cameron's government brands disabled people scroungers

The same is true of labelling. For example, tell someone how generous or how clever they are often enough and there’s a good chance that they’ll look for opportunities to prove it (providing, of course, that they like the label you give them). Even our self-concept is open to manipulation by those who know how to use selective abstraction to full effect.

Selective abstraction is a psychological spandrel that really does have serious consequences.

Confirmation bias is very much related to selective abstraction. Indeed, if confirmation bias is the ‘intention’, selective abstraction is the ‘mechanism’ by which we lead ourselves astray. It’s possible that confirmation bias and the perceived need to be right (or to be seen to be right) is also related to the drive for status and dominance but it’s no less dangerous for that.


We touched upon the process of confirmation bias in part 2 when we discussed what Karl Popper described as the demarcation problem: the difference between science, psuedoscience and nonsense. Science works because it only accepts what it cannot disprove and the scientific method is all about sincerely attempting to disconfirm hypotheses. In so doing scientists are careful to consider all the available evidence. Psuedoscience and nonsense focus only upon confirmatory evidence via selective abstraction and so fail to make meaningful new discoveries.

Confirmation bias serves to blind us to reality and exacerbates our mistakes.

Arbitrary inference


The ability to plan ahead, to imagine the future is a rare trait within the animal kingdom. It’s been a real advantage to humans. It’s also based upon the ability to recognise patterns and to predict what they will look like over time. And just like other pattern recognition modules it’s open to error.

When we predict the future we’re making an inference. We take what we already know and imagine how things we already understand will play out over time. Sometimes our inferences are based upon sound evidence but not always. Sometimes they’re based upon beliefs and ideologies that are not remotely evidence-based. These inferences are arbitrary.

The trouble with Arbitrary inference is that a single error can have dramatic consequences as each new assumption compounds the problem. Consider the following example…

John and Mary are engaged. They have been together for 5 years (living together for three years) and plan to wed in a few months. One night Mary tells John that she’s going out with some old friends. John makes several arbitrary inferences….

Mary’s going out with her old friends
That crowd used to go out ‘on the pull’
Mary’s going out to get laid
Mary can’t be trusted
Mary doesn’t love me
Mary wants to break it off
Mary will leave me soon
If Mary dumps me I’ll be humiliated
I should dump Mary first

Clearly this is a fairly dramatic example but these things do happen. The problem isn’t with our tendency to recognise patterns though, it’s with our tendency to accept patterns uncritically. The thing all these psychological spandrels have in common is their lack of critical thinking.

If we are to overcome our evolved tendencies to mislead ourselves and those around us we must begin by developing the habit of true deliberation and by accepting the fact that our initial assumptions may be wrong.

Hard wired 2: How we know what we know

Charles DarwinIn many ways this chapter may be the hardest for me to write. That’s not because evolution is particularly complicated but because it’s so obvious. At least it is to me. But it wasn’t always like this. There was a time when I really struggled with the whole concept of evolution. Again, that wasn’t because it’s complicated – it was because I really didn’t want it to be true.

However, regardless of what I wanted to believe all those years ago, evolution is true – it is a fact as indisputable as gravity or heliocentric theory (the notion that the earth revolves around the sun and not vice versa). In fact we have more evidence for the fact of evolution than we have for the theory of gravity, heliocentric theory, or even most of what we think we know about quantum mechanics.

So why did I once find it so difficult to accept evolution? The answer to that is both simple and complicated….

I found evolution to be challenging because I was a fundamentalist, creationist Christian – a ‘young earth’ creationist at that and evolution contradicts most of what I chose to believe. That’s the simple part.

I was a fundamentalist, creationist Christian for a variety of reasons, mainly social and based upon a need to ‘belong’. That’s the complicated part.

I’m aware that some readers of this blog – some of whom are good friends of mine will find these concepts just as challenging as I once did. To those people I say this…..

I have no wish to attack you and nothing that follows is intended to offend anyone. However, this information is based upon the best available evidence, at least the best evidence available to me – evidence which I will try to introduce as this series progresses.

But first we need to say a little about the nature of evidence, how we know what is true (or at least how we make our best guesses) and how we know when something is likely to be false. This will involve a little detour before we begin talking properly about evolution and evolutionary psychology – bear with me.

Science 1By far the easiest way to test whether something is true is to see if it can predict what we might find in the real world. That’s why scientists come up with hypotheses (possible explanations for stuff) and then devise tests to see if what really happens is what we would expect according to the hypothesis. Hypothesis really means ‘an explanation with little or no supporting evidence’. The more tests the hypothesis passes the more evidence it acquires to support it until eventually it moves beyond the status of hypothesis and becomes a ‘theory’.

Hypotheses with loads and loads of supporting evidence are still technically just theories although in common language they become known as facts. That’s the situation with the theory of evolution. It’s still a theory because in science everything is only a theory – an explanation that is supported by evidence – but nothing is a fact because there’s always the chance that new evidence might arise to disprove it. In fact the bulk of scientific testing is designed to try to find conflicting evidence, to disprove theories. If no evidence can be found then the theory is accepted provisionally. But the moment evidence is found that proves it cannot be true the theory is abandoned. That’s how science works. The process of trying to find evidence to disprove a theory is known as ‘falsification’. Remember that term – it’s really important. Falsification.

It’s a bit of a paradox but we can only really know what’s true by trying to disprove stuff – trying to prove our theories are correct doesn’t work. Here’s why…

Let’s assume that I have a hypothesis – I suspect that all mammals live on the land and so I set out to prove it. I go to the internet (doesn’t everyone use the internet these days?) and I type into a search engine ‘land-dwelling mammals’. Instantly I’ll find loads of evidence confirming what I already thought and I’ll be more convinced than ever that my hypothesis is correct. I’ll elevate my hypothesis to a theory because I have the evidence to support it – even to ‘prove’ it but I’ll be wrong.

Dolphin 1Had I typed a different search term into my computer I’d have come up with a completely different result. If I’d looked for the evidence against my hypothesis instead of just trying to confirm it I’d have a much better way to test it. What would happen if I searched for ‘sea-dwelling mammals’?

Instantly I’d have been confronted with images of whales and dolphins and my hypothesis would crumble before my eyes. I’d know that my hypothesis was incorrect and I’d have to modify it. I’d eventually end up, as most people already know, with a hypothesis that ‘most’ mammals live on land but that there are a few exceptions. Such is the power of ‘falsification’.

This idea is so powerful that a famous philosopher of science called ‘Karl Popper’ suggested that falsification is the key condition when trying to solve what he called the ‘demarcation problem’ – the difference between ‘science’ and ‘psuedoscience’ or even ‘science’ and ‘nonsense’.

‘Psuedoscience’ and ‘nonsense’ seek only to prove their claims whilst ‘science’ seeks to disprove hypotheses and theories – it seeks to ‘falsify’ claims.

That’s why scientific ideas progress. As each hypothesis or theory is disproven, scientists modify their beliefs and retest, all the time coming closer and closer to reliable truth. Psuedoscientists and nonsense merchants do the opposite – they seek only to find evidence that supports their existing beliefs and ignore or suppress ideas that contradict them. This process of looking only for supporting evidence is what researchers call ‘confirmation bias’, a tendency that scientists work hard to ‘factor out’ of their research methodologies. The confirmation bias lulls us into a false sense of security, even a false sense of competence – we believe that we were right all along and so we don’t ever try to improve upon our existing beliefs.

That’s why creationism hasn’t really changed for thousands of years whereas the theory of evolution keeps getting more and more refined and so more and more reliable. It’s because of this process of falsification. The attempts to falsify evolutionary theory mean that the overall picture is continually refined. We now talk about the ‘modern synthesis’ of evolution – a significant improvement upon Darwin’s original idea which, however brilliant it was (and make no mistake Darwin’s theory was brilliant) was incomplete. Modern theories are also incomplete but they’re getting better and better with every research study. So much so that although some of the fine details are still being refined we now have more than enough evidence to talk about the ‘fact’ of evolution in all but the very strictest, scientific terms where ‘theory’ is as certain as one can ever be.

That’s because, if it wasn’t true, evolution would be easy to falsify. The esteemed English biologist JBS Haldane, when asked what discovery would falsify evolution retorted:

“Fossil rabbits in the Precambrian”

That’s because, according to the theory of evolution (and it is a theory – it’s not just a hypothesis) rabbits didn’t evolve until well after the Precambrian era (around 500 million years ago) so fossil rabbits in those early geological layers would pretty much discredit all (or at least most) of evolutionary theory. In fact, almost any ‘out of time’ fossils would be a major problem for evolution and a number of organisations have dedicated themselves to trying to find such an anomaly – so far without success.

Remember the principle of falsification – the more you try and fail to falsify a concept the more reliable it becomes.

Contrast this with the idea of creation by intelligent design (the latest incarnation of creationism). It’s hard to think of a single piece of evidence that would falsify creationism because whatever evidence we throw at the problem the creationist will simply say that God designed it that way. Creationism is ultimately unfalsifiable (at least by its own standards) and therefore it’s impossible to prove as well. It’s a perfect example of what Karl Popper would describe as ‘nonsense’ or, in its latest form of ‘intelligent design’ (ID for short), ‘psuedoscience’.

You see the evidence is the thing – that and the lack of sought after falsification. That’s how we know what we know and also why we don’t have to base our beliefs on the origin myths of a handful of middle-Eastern desert nomads who lived several thousand years ago and knew nothing more about genuine scientific inquiry than their ancient Egyptian counterparts who worshipped Osiris and Ra.

The image below is a late addition to this blog, having actually been created for a different post in September 2014. However, it fits here very nicely as well.


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