“The difficult we do immediately. The impossible takes a little longer.”
This cheeky slogan, on postcards, mugs and screensavers, provides as much encouragement and motivation to modern office workers today as it did to the US Army Corps of Engineers during the Second World War. Whoever coined it, though, was certainly not talking about human decision-making, as the opposite might well be the case: tough decisions take a while, but impossible ones are easier. Take, for example, the choice about whether the UK should leave or stay in the European Union. The array of possible consequences from this choice is so vast and so monumental, it is, if not impossible, certainly the most complex decision most people have ever faced.
A vote to leave could impact every area of the UK’s relationship with what would be left of the EU. Some of the affected domains are obvious, but there are doubtless others that are less familiar, and some that a good many voters might not even know exist. The implications of a ‘Brexit’ would also be spread over a long period of time; some changes would take effect almost immediately, whereas others would manifest themselves only after a number of years, or even decades. So, long-term forecasts of our overall satisfaction with an outcome would have to take into consideration not only what we might get, but also whether we will still want it by the time it arrives. Finally, whether the choice will lead to a desired outcome is not solely in the hands of the UK; much will depend on how the EU and third-party countries respond to the British departure, and on how the UK responds to those responses.
Life is no easier for the Remain camp. They face almost identical challenges because they cannot confidently predict what EU membership in the future will bring, or whether they will like it when it arrives. That unknown future might not even be the same as the one they might have contemplated just a few months ago. This is because a country is irrevocably changed by the decision to vote on its membership of a union, whether it results in a split or not. Merely asking the question changes the relationship (try asking your partner how he or she feels about the idea of a divorce). So there is no status quo. The choice is between ‘out’ and ‘in-after-having-seriously-entertained-the-idea-of-out’.
A strictly rational referendum choice would require a decision tree with an almost infinite number of branches, all labelled with probability weights, of which some cannot be known. Even if we knew all of the possible future permutations and weights (and could agree on a definition of ‘good’ and ‘bad’), it would take the processing power of a supercomputer to generate the probability estimates of the vast array of possible outcomes. In short, the question is intractable. So, how does the human mind grapple with a choice so complex it is impossible to solve rationally? Easy. We reformulate the problem into a simpler form that we can solve. This is known as heuristic decision making.
One heuristic method is to abandon any attempt to optimise the decision outcome, and to concede that one cannot possibly know which choice would lead to a better or worse outcome for the country. Without much concern for the destination, one simply chooses the path on which one is happier to travel. For example, if given the choice, most people would prefer freedom over slavery, even if told that the slave-master is both wealthy and benevolent. The path is what matters for the decision, not the destination. This might be the mental strategy employed by those who seek to shed the perceived binds of EU control at all costs; be it rags or riches, let it be self-determined. The same heuristic is just as easily deployed by those who fear a ‘leap in the dark’. This group is no better informed about the ultimate outcome of their choice; they simply prefer to travel on a path they perceive as less ambiguous. In one study, conducted ahead of the Scottish independence referendum, such risk aversion was a better predictor of individual voting intentions than age, sex or national identity.
A choice based on the path rather than the destination seems to be a reasonable way to deal with an intractable problem, but sadly only in foresight. In hindsight, when one reaches one’s destination, few will actually draw much consolation from their perceived self-determination, or from their lower perceived risk, if the outcome is inferior.
Another, more common heuristic for tackling complex decisions is to focus on a few salient features of the choice, and to seek to optimise only those. For some voters, the focus might be on British exports, the City of London, or on EU immigration; for others, it might be the environment, human rights, or the ability of Premier League football clubs to recruit European players. It is obviously far easier to identify potential outcomes across a few salient dimensions, and to estimate their corresponding probabilities, than it is to grapple with all of them. Furthermore, if every voter does the same, it might even be possible to make a good choice, collectively. This is because the issues that are predominant in each voter’s life, the problems he or she encounters most frequently, also tend to be the most salient.
Like so many decision-making heuristics, though, the gains in computation time come with some drawbacks. The principal one, in this case, is that although predominant issues are salient, not all salient issues are actually predominant in voters’ lives. The salience of any given issue is heavily influenced by how recently one was exposed to it, how dramatic it was, or by the context in which it was presented. As a consequence, the very latest EU-related headline, a particularly tragic news story, or a flamboyant speaker, could determine what is salient for voters, whether or not the issue has any meaningful impact on their lives.
The complexity of this decision means that a reliance on heuristics is unavoidable. It can, however, be desirable if used properly. So, when considering the UK’s position in or out the EU, voters must reflect on what is important for them, rather than on what they perceive to be in the interests of the country. They must also ask themselves whether they will really care whether the UK is in or out as long as, in the end, their individual needs are met.
 Henderson, A., Delaney, L., & Liñeira. R. (2015) Risk and Attitudes to Constitutional Change. ESRC Scottish Centre on Constitutional Change