The parental immunity doctrine is a long-standing legal principle holding that minor children can't sue their parents for tort-related claims, and parents can't sue their children either. The general idea is to avoid undermining parental authority and control over his or her children, and also to maintain the peace of the family unit.
Most courts adhere to the 1891 Mississippi Supreme Court ruling in Hewlett v. George in which it was found so long as a parent is under obligation to care for the child, the child is under the reciprocal duty to aid, comfort and obey. Criminal laws will provide children protection from parental wrongdoing or violence, the theory goes.
But, there are many exceptions to this doctrine. It's not an issue that comes up often, but it did recently arise in the North Carolina Court of Appeals case of Needham v. Price, where it is alleged willful and malicious injury was caused. In those cases, parents cannot expect immunity, and that's how the appellate court ruled in overturning a previous summary judgment favoring defendant father.