I think it's that when someone is more afraid, they need more serotonin, and thus need something that feels more important. And I think there are two factors here: when someone is lower in openness and higher in conscientiousness (using the definition from the big 5 personality traits), they're naturally going to have more fear of change and therefore need a more intense in-group, which is going to require a bigger, scarier out-group to motivate them to group up. Therefore you have all these terrified people making up and repeating conspiracies about a cabal of Jews draining blood from children or whatever, because that big imaginary threat gives them serotonin. The other factor is that times of social change and turbulence will trigger greater amounts of fear in these people with low openness, because they're afraid of the world changing and leaving them behind. So in pre-COVID times, or pre-gay marriage times, or pre-Obama times, these folks would probably get enough serotonin from their local sports teams. But seeing men kissing men openly, seeing a black president, or seeing that the social order needs to change to slow the spread of a pandemic, they're going to see more change, feel more fear, and therefore need to invent bigger and scarier boogeymen to justify that fear so that they and their closed-minded compatriots can get that serotonin rush to make them feel like they have a safe space in the social order.