Brexit dominates political debate in this country to a staggering extent. The issue has barely been off the front pages or the news bulletins since the referendum campaign of 2016. Yet blanket coverage has not resulted in a well-informed public, as a new study carried out by the Policy Institute at Kings College London, the UK in a Changing Europe and Ipsos MORI has found.

Two-thirds of the public have heard the claim that the UK sends £350million a week to the EU, and 42% of these still believe it is true, despite it being labelled a ‘misuse of statistics’ by the UK Statistics Authority. 

The public overestimates the proportion of the UK population from an EU country by a factor of almost three – believing it is 16% rather than the 6% at which it currently stands.

Large proportions of the public think that European immigrants take more money out of the system than they pay in taxes, that immigration results in increased crime levels and decreased quality of health services.  The Migration Advisory Committee (MAC) recently published an independent report, commissioned by the government, that shows each of these is wrong.

Clearly this matters, and all the more so given the renewed interest in another referendum on our EU membership.  But let’s not expect any future votes to be any more informed, or less emotional, than the first time round.

It’s tempting, particularly for academics trying to provide accurate information, to put this down simply to spin and the fact people have been misled. This is certainly the approach adopted by proponents of another referendum – better information will lead people to vote the ‘right way’, or at least with ‘informed consent’.

But that’s only half the story. What we hear from politicians and the media does not, on its own, entirely shape our perceptions of realities. These are also the result of how we think, or, to put it another way, of our own biases.

Specifically, people’s perceptions can also be explained in terms of two key psychological concepts, as outlined in the Perils of Perception.  First, ‘emotional innumeracy’ describes how, when we’re worried about an issue such as immigration, we inflate the figures in in our heads.  We overestimate what we worry about, as much as the other way round.

And, second, ‘directionally motivated reasoning’, where, for example, some of us are already suspicious of how much the EU costs the UK, so we’re happy to believe the £350million claim, and dismiss or avoid contrary evidence. What we already think, in other words, colours our view of reality.

This is not a new phenomenon. Similar patterns can be observed on a number of issues at different times in history across different countries with very different media and political contexts. 

The bottom line is that emotion and identity are key to how we perceive reality.  And, Brexit has revealed new strong identities associated with ‘leave’ and ‘remain,’ as the chart below shows, which in turn have spawned different views of reality.  Indeed, prominent psychologist Daniel Kahneman argued prior to the referendum of 2016 that anger and irritation could lead to Brexit.

And we can see how much these strong identities colour views of reality in our latest study: only one in five Remain supporters believe the £350million claim, compared with two-thirds of Leave supporters. 

This realisation is crucially important in terms of the debate around another referendum on EU membership. AC Grayling, outspoken remain cheerleader, argued that a second referendum was necessary ‘now we know the facts.’

Yet the stickiness of views around Brexit has significant implications for those who argue that a ‘better,’ more ‘fact based’ campaign can persuade people to change their vote. For example, since 2016, there has been barely any shift in how many believe the £350million claim, or whether Brexit will improve people’s own standard of living or in our guesses at immigration levels. 

And where we have seen changes, such as in increasing concern about Brexit’s impact on the economy, this hasn’t led to more than a slight softening of support for leaving, as the charts below show. 

So does this mean facts are useless, and we should give up trying to inform people better?  Not at all.  It’s just as wrong to conclude we’re driven entirely by our emotions and identity as it is to think everyone rationally considers new facts and instantly changes their world view as a result.  People are varied and complicated, and our communications need to reflect that.

Some people have started to set up stories and facts as opposites, when they’re not. Or to think people can only be either rational or emotional but not both, when that’s not how humans work.  The key is to understand the crucial role that stories and emotions play, while remembering that reality still matters, and it can bite.

Professor Bobby Duffy is director of the Policy Institute at King’s College London

Anand Menon is director of The UK in a Changing Europe and professor of European politics and foreign affairs at King’s College London