Reading 1.7: The limits of mental modelling
We are constantly reminded in the media how intellectually and emotionally 'superior' we are to other species on Earth. The locus of this superiority is apparently our brains. By the time our species reaches adulthood, our ratio of brain size to body size (the 'encephalisation quotient') is three times greater than our closest relatives, the primates. This large brain allows us to escape what Christopher Wills (Wills, 1993) in his book, The Runaway Brain, called 'stupid-world', a place made up of animals unable to switch off their senses from the constant bombardment of immediate environmental stimuli. True, many animals are able to explore a situation, observe their impact on themselves and evaluate the effects, and then plan avoidance or remedial actions. But we have evolved this into a fine art. Our greatest difference is our ability, during our waking moments, to detach ourselves from the here and now (our actions and observations) and develop mental models of our surroundings (our reflections and plans).
Yet, we are not as clever as we think we are. In his 1956 paper entitled 'The magical number seven, plus or minus two: some limits on our capacity for processing information', cognitive psychologist George Miller (Miller, 1956) demonstrated that most of us cannot hold more than seven or so different items of information in our heads at any one time.
The fact that most people cannot hold more than seven items of information at the same time has major consequences. Our view of a situation will always be a simplification of reality, because we can only deliver and people can only absorb 'seven, plus or minus two' items of information at any one time. Thus, whether the delivery mode is oral, written, visual or mathematical, it is useful to think about developing a communication experience that does not overload the senses with more than seven items at a time.
A second issue in developing and communicating mental models, is that people frequently develop their models of reality based on existing ideas and opinions. Thus, we select information based on past experiences and current beliefs rather than looking for things that might contradict these. It is also appropriate to think of your listener's past experiences and current beliefs in communicating your mental model. This phenomenon of 'selective perception' can be crudely described as 'people see what they want to see'. It is therefore very difficult to let go of your beliefs and experiences, even if there is mounting evidence that your mental model might be inappropriate.
One of the consequences of 'selective perception' is the self-fulfilling prophecy phenomenon. If you develop a mental model of yourself which says 'I am ugly and fat', then you will most probably avoid situations which focus on your physical appearance: swimming in public; dancing and wearing tight clothes; asking somebody out for a drink; and so on. As a result, you stop being invited out and may have problems finding a partner. Challenged, you might answer 'but that is because I am ugly and fat'. In this situation you are trapped in a vicious self-fulfilling mental model. And it is often impossible to escape from this trap because of another key human characteristic: face saving. It is amazing to see how many people refuse to admit they are wrong even though such an admission would allow them to move on with life. In fact, there is usually no such thing as a clear-cut right or wrong answer – just partial perceptions of reality.
A third issue is the tendency to focus on the detail rather than the bigger picture. It is far easier to specialise in a particular area we are familiar with rather than sweep in more information we are not particularly comfortable with. For example, most of my scholarship involves engagement with ecological research and literature, although it would probably benefit my understanding of the complex reality out there if I also engaged with other disciplines, including economics – but the idea of reading a book in economics is certainly not at the top of my 'to-do list'. As a consequence, most mental models are piecemeal and rarely address the full complexity of the problem at hand. Although related, the tendency to specialise is a distinct issue to that of 'selective perception'. We can select information based on past experiences which have led us to specialise in certain fields and/or opinions. In essence, our wish to specialise our mental models is mostly due to impatience – we want to quickly arrive at the root cause of a problem, whereas in reality there is seldom a single overwhelming factor which controls the outcome of a situation. Once again, there is no right or wrong answer, just a partial perception of reality, this time resulting from specialisation.
A fourth issue to consider is 'group think'. Solomon Asch (Asch, 1963), a world renowned gestalt psychologist, carried out a fascinating experiment to investigate the effect of groups on individual decision making. He placed a group of people in a room and presented them with two cards: one of the cards had a single straight line drawn on it; the other one had three lines of differing lengths, one of which was identical to the line on the first card. The group's simple task was to select the line in the second card which matched the line on the first card. All the individuals in the group, except for one, were secretly asked to provide the wrong answer. Sometimes the group was asked to provide their opinion before the unsuspecting individual's turn and sometimes after the unsuspecting individual provided an answer. The results were startling. Those individuals asked to provide their opinion after the rest of the group, gave a wrong answer 40 per cent of the time. Those individuals asked to provide their answer before the group, always got it right! Thus, some ignored the blatantly obvious in favour of accepting the opinion of the group. It is fascinating to observe these phenomena in society, where individuals are induced to carry out acts in a group setting that they would never do on their own.
The fifth issue is the difficulty in dealing with dynamic situations that do not correspond to our perception of space and time. In his book, The Blind Watchmaker, Richard Dawkins despairs with our limited capacity in dealing with unfamiliar timescales:
... our brains are built to deal with events on radically different timescales from those that characterise evolutionary change. We are equipped to appreciate processes that take seconds, minutes, years or, at most, decades to complete. Darwinism is a theory of cumulative processes so slow that they take between thousands and millions of decades to complete. All our intuitive judgements of what is probable turn out to be wrong by many orders of magnitude. Our well tuned apparatus of scepticism and subjective probability-theory misfires by huge margins, because it is tuned – ironically, by evolution itself – to work within a lifetime of a few decades. It requires effort of the imagination to escape from the prison of familiar timescale ...
Even the issue of space is a major challenge. It is only relatively recently that our species has come to terms with the fact that the Earth is round and not flat. This realisation is almost out of reach of our cognitive abilities. The fact that below me, rather than to my right (I am looking out of a north-facing window), is my 'upside down' Australian colleague still boggles my mind.
Our inability to deal appropriately with a wide range of temporal and spatial scales is probably why we have such immense problems in understanding and redressing major threats such as climate change. We can react to situations that we understand and that affect our lives directly, but it is not always so easy to do this in situations where the event has not even happened and there is no direct understanding of how these events will affect us over time and space.
The final issue (and I have left this one until last on purpose) is our limited attention span. Although I have not yet reached the 'magical number seven', I would not be surprised if your attention has started to wander – as I write this I am certainly feeling like taking a break! It is no coincidence that most meetings, lessons, films, sports events and other activities that require one's attention rarely last more than one and a half hours; and even these periods are broken up into smaller units with peaks and troughs of mental activity.
Although we need to concentrate in order to develop our mental models, the fact that most people have a time limit on how long they can concentrate is a good thing. Historically, we needed to occasionally detach ourselves from our mental exertions and scan the environment for predators and/or enemies. Some individuals have the luxury of being able to concentrate for an extended period of time only because we have evolved a society which looks after them. Increasingly, we are delegating the 'looking after' to technology, in the form of washing machines, industrial agriculture and food processing, online shopping, etc., so a greater proportion of society and individual's time can be dedicated to mental modelling.
But this does not change our biological limits – we still need the same time that humans always have for developing our own mental models and understanding the models of others.
So, recapping on the issues that you need to be aware of when developing and communicating your mental models:
- You can only hold seven (plus or minus two) items of information at any one time.
- You develop your mental models based on past experiences and current values.
- You tend to focus on the detail rather than the bigger picture.
- Given the option between choosing your own judgement and that of the group you are part of, you have a tendency to be strongly influenced by the latter.
- You have a limited attention span, so any mental model must be developed or communicated within units spanning no longer than one and a half hours.