Venables and Thompson weren't normal kids. They had family lives where they'd witnessed and been subjected to violence over a long period of time, some of it extreme. Not violence in terms of the smackings that most kids in the 80s were subjected to. Their homelives were chaotic and were a fundamental reason for their offending. The case of the two brothers in Doncaster which has a hair's breadth from becoming a similar murder bore the same hallmarks. They were from extreme environments. This is not a guarantee of extreme behaviour but makes it much more likely. Take 100 kids and put them in Thompson and Venable's situations and let's say 20 of them go onto do something very violent. Take the same hundred kids and put them in a loving home and you change that number to ,say, 2.
I'd say they were normal kids - When the papers went round Liverpool interviewing anyone who'd give them the time of day, didn't some local scal make the point that "There's nothing special about them, they're just your average scruff like us"? I'm sure they did. They were normal kids for that place and that time.