Arthur "Boo" Radley had gotten into some trouble with the law as a young man and, rather than him serving time in jail, his father agreed to deal with the situation himself. His solution was to restrict Boo to the Radley house. We can assume that this social isolation caused Boo's emotional problems, and he became a recluse within his own home. He apparently only ventured out at night when no one could see him. He may not have been physically abused, but the emotional abuse perpetrated by his father no doubt contributed to his deteriorating mental state. Calpurnia called Boo's father "the meanest man alive," at least in part because of his treatment of Boo. Mr. Radley was also a strict "foot-washing Baptist," and he was considered a bit too high-and-mighty by many of Maycomb's citizens. The neighbors stayed out of the Radley's personal business, probably in part because many of them feared Boo. Some people, such as Atticus and Miss Maudie, knew better, and remembered him as a decent person before his forced isolation.