[rawgabbit]

As an anecdote, I have a couple of elderly family members who did not mellow with age. Instead they became even more toxic and abusive as they approached their 80s. (I have another who was the complete opposite.). The abusive ones hurled curse words as soon as you entered the door; then they "switched" personalities and acted as if nothing happened. I also know of an acquaintance whose son had the similar personality traits even though he's only in his 40s. The son needed a 24 hour a day caregiver because he's mentally challenged. In short there are a whole host of physical and/or mental problems that confound the situation.