Some psychologists say that when we meet a new person we instinctively and subconsciously evaluate them for trustworthiness and competence.
In tribes we were able to know who to go to for advice on repairing shoes or clothes or medicine or marriage advice. We knew the experts personally and trusted them. Now we live in towns and cities. We go to trusted experts to mend an old jacket, to repair our teeth, to fix our cars and for medical care. In some areas of knowledge, however, we may find it difficult to know who to trust and we turn to word of mouth recommendations. Maybe we google them or look up reviews.
Conspiracy theorists don’t trust authority and why should they? Politicians routinely lie to the public. Some countries have corrupt or bias policing. Businesses can have hidden agendas. So who are the experts we can trust?
For example I have never met Professor Dawkins. Why should I trust him? Why should I trust unknown experts in government advisory positions or in academia. My own personal experience tells me that people climb the greasy pole though aggression and greed not competence and trustworthiness.
Yet this feeling is as misleading as it is widespread. Actually the majority of professional experts are reliable and non-professional self-professed experts less so. Basically if people are willing to pay you because of your well-established expertise then that means something. If is part of scientific education to become skeptical but also discerning and to develop a good gut feeling for reliable sources of information. Of course we could repeat the experiments to double check but if you do that with every item of scientific knowledge you come across you would never have time for the validation needed. So we trust professional and reputable experts. That is reasonable. Conspiracy theorists lack trust and lack the gut feeling for what is a reliable source of information and what is not. Arguing science with a conspiracy theorist will rarely change their mind. Maybe instead of pitting scientists against conspiracy theorists in debates, it might be better to pit psychologists against conspiracy theorists in public debates. That would go to the root cause, their lack of trust in authority.