Polls show that most people believe in at least one conspiracy theory. Considering the number of conspiracy theories there are, perhaps this isn’t surprising. But research shows that people who believe in one conspiracy theory are more likely to believe in others.

Part two of the Expert guide to conspiracy theories, a series from The Conversation’s Anthill podcast, discovers who these people are. We find out what psychological factors influence whether you believe in conspiracy theories or not. And how things like the time and place that you live, who your friends are and who holds political power makes you more open to certain conspiracy theories.

Jan-Willem van Prooijen, associate professor of psychology at Vrije Universiteit Amsterdam in the Netherlands, explains his theory that humans are hardwired to believe in conspiracy theories. He says the circumstances of hunter gatherer life meant that our ancestors adapted to be overly suspicious.

Times have changed but humans are stuck with this hangover from hunter gatherer times that we sometimes struggle to shake. We speak to psychologists Karen Douglas and Aleksandra Cichocka at the University of Kent in the UK to find out why certain people today are more likely to believe in conspiracy theories than others.

We find out how political beliefs influence whether or not people believe in conspiracy theories. Joseph Uscinski, a political scientist at the University of Miami in the US, talks us through his theory that people who vote for the losing side in an election are more likely to believe in conspiracy theories than those on the winning side.

For a slightly different perspective on who believes in conspiracy theories, we talk to anthropologist Annika Rabo from Stockholm University in Sweden. She spent many years in Syria doing fieldwork and tells us how talk about conspiracies permeates society – it’s unavoidable. There are all sorts of conspiracy theories and they relate to the US, to Israel but also their own government.

Jovan Byford, a social psychologist at the Open University in the UK, explains why it’s important to understand the historical context in which certain conspiracy theories emerge and flourish. He points out that the status conspiracy theories are given in society influences how popular they are and that not everyone engages with them in the same way. Some take conspiracy theories seriously, but others don't and engage with them for fun.

The Anthill podcast is produced by Annabel Bligh and Gemma Ware. Sound design is by Eloise Stevens, with original music from Neeta Sarl and audio from Epidemic Sound. Thanks to City, University of London, for letting us use their studios to record. Special thanks to Clare Birchall, Michael Butter and Peter Knight who helped bring this podcast into being, and to the COST Action COMPACT for funding it.