YOU might expect a journalist to be a fan of adopting a ‘healthily sceptical’ view of most things and you would be right.

A reporter’s job is to talk to as many sources as possible – official and unofficial – and build a facts-based article.

There should be evidence to back up the story and, ideally, on-the-record quotes from an expert. The end result should be a story that is accurate and fair.

Running entirely separately to this is opinion. Opinion can be challenged and argued with, whereas facts are facts and cannot be disputed.

The problem is that quite a lot of people just can’t or won’t see the difference and they are unconcerned about mixing up opinion with fact. It’s a disturbing trend.

A survey carried out by YouGov and the University of Cambridge published this week discovered that those with strongly held populist attitudes had the clearest tendency to believe in conspiracy theories, despite them being contradicted by science or factual evidence.

This is interesting and worrying in equal measure, as it has been the hallmark of Donald Trump’s presidency.

Through Twitter (and sometimes in gobsmackingly inept press conferences) the US president has undermined efforts to address issues such as global warming and he regularly dismisses fact-based journalism as “fake news”.

This is alarming because the phrase ‘fake news’ has become widely used to describe any article that someone doesn’t agree with, even though it might be completely factual.

It is exemplified by the battle faced by public health officials who have seen a huge rise in the number of outbreaks of measles around the world amid increasing numbers of unvaccinated children.

In 1998, discredited physician Andrew Wakefield published fraudulent research in the Lancet which suggested that the measles, mumps and rubella vaccine (MMR) vaccine had a role in causing autism.

Understandably, the subsequent articles caused much panic among parents. A decline in vaccinations in many parts of the world have been attributed to the publication of that ‘research’, which led to a belief that there is a connection between vaccines and autism.

It has given rise to the ‘anti-vaxx’ movement, which appears to be growing and to the concern of medical experts is gaining traction thanks to social media. GP Dr Sarah Jarvis was clearly extremely frustrated and worried when she spoke on BBC Radio 5 Live last week about this increase in the number of cases. It’s a disease that can have very serious consequences, including death.

The scientific evidence is now unequivocal – there is no link between the MMR vaccination and autism, despite Wakefield’s assertion otherwise. He apparently continues to peddle this myth to people in America and his discredited scare stories have led to many deciding not to vaccinate their children in the States. Healthy scepticism when presented with a ‘fact’ by someone in power is important, but that must be followed up with checks and research. Too many people ‘like’ and retweet the most ridiculous lies published on Twitter – when that retweet perpetuates the MMR/autism myth, the consequences could be lethal.