People became informers for many reasons. In some case it was ideological, the conviction that there were enemies of the system to be rooted out. In other cases it was coercion. It might be suggested to a school-leaver that their chances of a university place would be improved if they gave information about friends or peers. And for some it was money.
"On the whole they found that conviction was better than coercion," Hovestadt said. "They were skilled at making it not feel like betrayal, but a valuable service to the country. They played on people's self-importance."
Even the most egregious betrayals, of a spouse for example, could be portrayed as saving the person from something worse.
As people have searched their files they have often found that friends or even relatives informed on them.
But often the process brought closure. Someone might discover the reason they had not gained admission to a university was not that they were not smart enough but that someone had reported an injudicious comment.
Even the most trivial information could be useful to interrogators. Three days into an interrogation they might indicate they knew the person's favourite flavour of ice cream, say, leaving the victim to wonder "Is there anything they don't know about me already?"
