Immigration is seldom out of the news, but the past month has seen attention spike to new highs as the removal of transitional controls on migration from Romania and Bulgaria has sparked furious debate, writes Rob Ford. Many headlines suggest the British public is implacably opposed to migration, and demand radical action from the government to bring down migrant numbers.

The true picture, however, is more complicated, as revealed in data released today by the NatCen from the 2013 British Social Attitudes survey, which is the most comprehensive academic survey of British public attitudes.

That the public believes migration levels are too high is indisputable: 77% of respondents said migration should be reduced, with 56% wanting it reduced by “a lot”. But it is important to put this number in context. Pollsters have been asking British people this question for almost exactly 50 years, and in practically every poll, a hefty majority of 60-85% report that migration levels are too high.

The proportion demanding reductions to migration was as large in the 1980s, when net migration was negative, as it is now, when net migration runs at 200,000 per year. So the British view of migration levels does not respond to the actual migration level; it is like a thermometer which says the temperature is “too hot” regardless of whether it is 30C or -10C. It is not clear what this measure actually captures, but it seems to be more like a general view of migrants in general rather than a response to current levels. Most voters regard migration as a bad thing to be avoided, so, just as any broccoli at all is “too much” for many children, any migration at all is “too much” for many voters.

We can dig a little deeper into British views about migration by moving the focus away from migration levels and towards migration impacts. The survey also asked respondents whether they thought the economic and cultural impact of migration had been positive or negative. Focusing on the effects of migration, rather than the number of migrants, reveals a very different picture.

Far from being a nation united in opposition to migration, Britain is instead a country evenly divided. In our 2013 data, 48% of Britons saw immigration as bad for the economy, while 52% saw it as neutral or good. The split on culture is similar: 46% seeing the cultural impact of migration as negative, and 54% regarding it as neutral or positive. Remarkably, given the harsh economic climate and the barrage of negative media attention, public perception of migration’s effects has improved somewhat since 2011. The proportion rating the economic impact as negative has dropped four points since 2011, while the proportion seeing a negative cultural impact is down two.

While the British public is evenly split over the impact of migration, attitudes are very polarised. The table below breaks down attitudes by economic circumstances and cultural factors, and reveals deep and enduring divides in views about immigration.

The majority of respondents who are well off economically, who had some migrant heritage themselves (20% of our sample reported that they or one of their parents were migrants), those who went to university and those who report no prejudice against ethnic minorities are consistently positive about the economic and cultural effects of migration.

On the other side of the coin, economically struggling Britons, those with no migrant heritage, those with no formal educational qualifications and those who report some prejudice against ethnic minorities are strongly negative about the effects migration is having on the country. While the divides endure, it is also remarkable to see that the improvement in views about migration is reflected in every single social group, and that in many cases the biggest improvement comes from those with the most negative views.

A closer look at the underlying attitudes thus reveals that the headline picture of a British public passionately and implacably opposed to migration is a misleading caricature. Instead, we find a citizenry divided over the effects of a dramatic social change – while many dislike it intensely, many others see it positively. Far from turning against migration over the past two years of economic turmoil, Britons from all walks of life have become somewhat more positive about it.

The difficulty for politicians trying to craft policy in this area is that the importance different groups attach to immigration is not the same. Those who accept or welcome immigration do not regard it as a pressing issue, and rarely base their votes on it. For its opponents, though, migration has become an all encompassing issue, and a principle determinant of vote choice: in IPSOS-MORI’s regular polls, more voters rate migration as one of the top issues on the agenda than any other issue except the economy, and almost all of these are opponents. It is no coincidence that Nigel Farage’s UKIP has won its strongest support from the very same groups the data reveals are most opposed to migration.

This difference in intensity may explain the common misconception that the public is uniformly negative about immigration. The negative voices are heard more loudly, and more frequently, which leads many to conclude their views are more widespread than is in fact the case. This helps those with the most negative views to drive the political agenda. With universities, businesses and economic researchers worrying that the current government’s restrictions to migration may be economically harmful, perhaps the time has come for the silent, pragmatic majority to speak up.

• This post originally appeared on The Conversation UK web site.