This isn’t simply about proximity; it is also about belonging. Our social nature means that we adopt beliefs as badges of cultural identity. This is often seen with hot-potato issues, where belonging to the right tribe can be more important than being on the right side of the evidence. Acceptance of climate change, for example, has become a shibboleth in the US – conservatives on one side, liberals on the other. Evolution, vaccination and others are similarly divisive issues.
So, what we come to believe is shaped to a large extent by our culture, biology and psychology. By the time we reach adulthood, we tend to have a relatively coherent and resilient set of beliefs that stay with us for the rest of our lives (see “Your five core beliefs“). These form an interconnected belief system with a relatively high level of internal consistency. But the idea that this is the product of rational, conscious choices is highly debatable. “If I’m totally honest I didn’t really choose my beliefs: I discover I have them,” says Halligan. “I sometimes reflect upon them, but I struggle to look back and say, what was the genesis of this belief?”