well I'm pretty sure the 3rd link is wrong, robert hare is one of the biggest people to research physcopaths and I'm pretty sure he says that physcopaths are calculated and cold ones. Also lack of empathy is physcopathic people with aspd can have emapthy. There are a lot of generalisations, misuse of terms/terms used interchangably but that is cos they are relatively new constructs. The main people who researches aspd and physcopathy came to see they were 2 different things, well I think most of the main people involved did. American and international ideas can differ too.