Let me explain why you might be hearing more about conspiracy theories at the moment.

According to Jan-Willem van Prooijen at the University of Amsterdam, conspiracy theories (CTs) proliferate whenever there’s a crisis, particularly one that causes rapid societal change and in turn creates fear, uncertainty and feelings of helplessness. The longer the situation continues and the higher the anxiety, the more attractive such theories become – particularly, according to Richard Moulding and colleagues at Deakin University in Australia, to those who feel isolated and powerless.

Aleksandra Cichocka at the University of Kent defines CTs as "secret plots by powerful and malevolent groups", and offers three reasons for their appeal. First, in the absence of clarity elsewhere, they offer an explanation for what’s going on. Secondly, they confer a sense of control over what’s happening. Third, that sense of control bolsters self-esteem.

According to Dr Cichocka, individuals who have a desire to be considered special – even unique – are more likely to adopt CTs, particularly if they also suffer low self-esteem. Dr van Prooijen suggests those who feel like outsiders are more likely to endorse them.

Viren Swami at the University of Westminster surveyed 990 British adults and found those most likely to believe in CTs use intuitive rather than analytical thinking to solve problems. CT believers are generally more anxious, and score lower on Open-mindedness, one of the Big Five personality traits.

Eric Oliver and Thomas Wood at the University of Chicago conducted four US surveys between 2006 and 2011, each canvassing around 2,000 individuals. They found 50 per cent of those surveyed consistently endorsed one or more conspiracy theories. These individuals were more willing to believe in unseen intentional forces and in Manichean narratives; that is, defining all conflict as a struggle between good and evil. However, neither political views nor amount of relevant knowledge was consistently associated with level of belief in CTs.

If someone endorses a CT you don’t agree with, what’s the best approach when they bring it up?

Don’t ridicule them or dismiss their views. This only lowers self-esteem further and increases anxiety, and makes it more likely they’ll maintain their views without thinking them through.

Do ask questions. Karen Murphy at Penn State University suggests: what’s your evidence; what sources back up that evidence; and what’s the reasoning that links the two? Also ask for the evidence that allows them to dismiss all other theories. This will help you both weigh up the validity of different explanations.

Use terms that suggest analytical thinking – for example, "reason, ponder, rational, logical".

Finally, make it clear you’re merely asking about their views; that your opinion about them as an individual has not changed.

The Daily Telegraph