Belief: What It Means to Believe and Why Our Convictions Are So Compelling

"This book is so comprehensive. It’s a very, very, big book, over 600 pages. James Alcock just sat down and thought about the topic of belief, from all possible angles that he could. He already knew a lot about paranormal beliefs and the psychology of beliefs in general, but he’s looking at it from all the different perspectives. When you actually sit down and think about where our beliefs come from, they come from lots of different sources. A lot of what we believe is not because we’ve got direct personal experience of that thing, but because we’ve been told about it by somebody else. You believe that we’ve gone to the moon or that the world is round or that there’s somewhere called Australia, even if you’ve never been. A lot of the time, we believe things because we are told them. So there’s the whole social influence: who you choose to believe and who you don’t choose to believe. At a more direct, personal level, you base a lot of your beliefs on perception and how you perceive the world around you. Again, there’s a lot more to perception than most people realize. Unless you’ve studied psychology, you have the view that we’re taking in all this information from the outside. There’s the homunculus model that you used to see in comics, this little person inside watching a cinema screen, and that’s your eyes. And so on. Of course it’s not like that. Perception and memory are constructive processes. We have a subjective impression that we are taking in all of this information in full color all the time instantaneously. We’re not. That’s an illusion generated by our own brains. There’s only a very small part of your retina that has color sensitive cells. The rest of the time, it’s your brain filling it in. You know that that wardrobe is brown. Although you think you’re perceiving it as brown on an instant-by-instant basis, you’re not: the only thing you’re seeing in color is what you’re directly looking at, which is a tiny area. There are lots of other examples like that. We have a lot of mistaken beliefs about how our own cognitive systems work. So perception is a constructive process. It’s generally accepted, certainly by cognitive psychologists, that we’ve got two sources of information when we’re trying to make sense about the world around us. On the one hand, there’s the sensory input, sometimes called bottom-up processing, so the information coming from your eyes, your ears, or your other senses. We also make use of what’s called top-down processing. That’s basically our beliefs, our knowledge, our expectations about the way the world is. These two interact constantly. We have a mental model of the world and our place in it. And we’re constantly updating that model on the basis of new incoming sensory information. But that does mean that on occasions, if the sensory input is inherently ambiguous, or it’s degraded in some way, then top-down influences become relatively stronger. So we might end up seeing things and hearing things that aren’t in fact really there. So perception itself can be misled. So one of the topics that Alcock covers in the book is the nature of perception and illusions, and so on."