This is an excellent, comprehensive examination of the things we believe, and why. It is a very well-written, well-organized book with a unifying theme: we form our beliefs, and then we rationalize them with explanations. We initially formulate our beliefs through two processes: patternicity and agenticity. Patternicity allows us to form all sorts of weird beliefs, including the whole gamut of superstitions. For example, if something bad happens when a black cat crosses your path, and at a later time something else bad happens in the presence of a black cat, it is natural for one to see "a pattern".
And, when we see a pattern--even in a series of coincidental occurrences--we often ascribe agenticity to it. We attach a special meaning, or ascribe the occurrence to an agent who has intentionally willed it to happen. Beliefs in haunted houses, lucky sweaters, seances, aliens, ghosts, and a host of other phenomena are due to agenticity.
Shermer shows how the biology of the brain and chemicals that activate neurons in certain regions of the brain can play a big part in forming our beliefs. Belief in the afterlife, in God, in aliens, in conspiracies, and political beliefs are all discussed in some detail. A whole host of biases in our beliefs are described.
Toward the end of the book, our scientific beliefs are described. The history of cosmology is told in some detail, offering insights into how old paradigms hold sway for years-decades-centuries-even millennia, until science has gathered overwhelming evidence for a better theory.
I highly recommend this book to anyone with an interest in how and why people formulate beliefs.