Biologically and psychologically, adolescence continues until around 25 years of age. Some young men don't get proper adult male muscle structure o hair growth until thrity-thirty five, and empathy doesn't seem to be completely developed in most people until the mid twenties, later in some. empathy is hard, though, because it can crop up in very developed forms in isolated situations very early (as early as toddler ages in some situations) and then disappear in the same child in other situations, so it has a patchy emergeance pattern, but most can't maintain it consistantly until about twenty-twentyfive. Not an easy question.