What caused the Salem witch trial hysteria of 1692?
There were both underlying causes and immediate ones. For one, the people of Salem in the late 1600s were both very religious, and very superstitious. So when the first accusations of witchcraft came up, they were more likely to believe it.
Secondly, the Puritan religion and preachers had conditioned the population to fear all things satanic, and to believe that they might not be able to control his influences.
Lastly, fear of witchcraft goes back centuries before this time, as did the methods of dealing with them.
The immediate cause was when accusations were made against a slave, Tituba, for practicing voodoo. People who had been with her were also accused, and all they could do to save themselves was to accuse someone else. It was a spiral of fear.
There are lots of explanations given for this. But, of course, no one can ever know the real reason. The people of the time would have said it was caused by the fact that witches are real. Historians don't believe that so they come up with other explanations. Here are a couple I like:
First, I have read speculation that the witch trials were caused by people having hallucinations due to fungus that they ate accidentally (it's supposed to have acted like LSD). I don't buy this one, but I mention it because it shows that historians have suggested a WIDE variety of reasons. I'm including a link to an article about that so you can see I'm not pulling your leg.
Second, some people say it happened because the society in Salem was under stress. They say that people lived in fear of the unknown (things like diseases) and of Indian attack. They say that their society was changing from one where all the people really knew each other to one that was more impersonal.