British people appear to have an in-built acceptance of risks and harms from motor vehicles that they would not accept in other parts of life, a study has discovered, with potentially widespread repercussions for how policy decisions are made.

Such is the cultural ubiquity of these assumptions, described by the researchers as “motonormativity”, that politicians are less likely to try to tackle issues such as pollution from vehicles or poor driving, they warned.

The study took a pool of more than 2,000 people and randomly assigned them one of two sets of questions that sought their views either on a driving-related risk or a near identical query on a wider issue, with just a couple of words changed.

In one example 75% of people agreed with the statement: “People shouldn’t smoke in highly populated areas where other people have to breathe in the cigarette fumes.” But when just two words were changed – “people shouldn’t drive in highly populated areas where other people have to breathe in the car fumes” – only 17% agreed.

Similarly, while only 37% of people thought the police needed to take action if someone left their “belongings” in the street and they were stolen, with the word changed to “car” it rose to 87%.

In another question, 61% of people agreed that risk was “a natural part of driving”, whereas just 31% agreed when “driving” was changed to “working”.

The study, led by Ian Walker, a professor of environmental psychology at Swansea University, found the responses stayed similar even when the researchers examined those only from people who did not drive.

Walker, whose previous studies included research that showed drivers tend to overtake male cyclists more closely then female ones, and to pass nearer to riders wearing helmets, said the new research illustrated the extent of the policy “blind spot” about driving and cars.

“It is nonsensical to say that making people breathe toxic air is a problem when it comes from a cigarette, but making people breathe toxic air is fine when it comes from a car,” he said. “The underlying principle is the same, but people in our study were not using the same standards when they judged the two things.

“It’s long been suspected that people can slip unconsciously into using different standards when they think about driving, leading them to commit a fallacy known as ‘special pleading’. Our study was intended to reveal this phenomenon and show just how substantial these effects can be.”

The impact on policy was clear, said Alan Tapp, a professor of marketing at the University of the West of England, who also conducted the research.

“If you asked a politician whether a new hospital should be inaccessible to one-fifth of the population, obviously they’d say no,” he said.

“Whereas if you asked that same politician whether a hospital should be built on the edge of town, it’s likely that many wouldn’t see the problem, if they have a form of this mindset we’re looking at. But in practice, having the hospital outside town is not that different from making it inaccessible when a fifth of households don’t have a car.”