At 02:57 in the clip below, right at the beginning of the interview that preceded the polygraph, Colorado Bureau of Investigation Agent Tammy Lee tells Chris Watts:

“You know if you did have something to do with their disappearance, it would be really stupid for you to come in and take a polygraph. [Laughs]. It would be really dumb.”

And so Chris Watts takes the polygraph, fails, and then goes on to confess largely because of the failed test.

There’s no doubt stupidity does play into the criminal psychology [and psychopathy] here, just as it did in the Scott Peterson case. And probably, elements of vanity and narcissism exacerbate [or inflate] this self-perceived sense of mastery [over others and one’s world].

But there has to be another aspect that accounts for the incredible poor levels of intuition going on here. Does being dumb lead to poor perception skills, or do poor perception skills drive dumbness?

Here’s a clue, and it’s one than can impact all of us.

What the Dunning Kruger effect suggests is the less we know, the more we think we know and tend to over-estimate our chances. On the other hand, the more we know, the more modest we tend to be about what we think we know.

In a criminal case, a criminal – like Chris Watts or Scott Peterson – may believe they know a great deal more about their crime than anyone else. Further, especially if there is premeditation and an extensive and elaborate effort to dispose of evidence [and the human remains], this sense of overconfidence is likely to be exaggerated.

It helps, in these circumstances, for the cops to play dumb, and to not reveal what they know. In both the Chris Watts and Scott Peterson cases, the cops knew about the affairs some time before the criminals knew that the cops knew.

But there’s another dimension to the criminal psychology that goes beyond all of this. It’s like the coldness of a psychopath but it’s not quite the same thing. Any person can become numb or unfeeling to someone else after a season of lying, duplicity and deceit. This behavior creates disconnection, and the murder is the final leg of that journey. It’s the final disconnect. In order to get to that place, the murderer becomes “standoffish” not only towards his intended victim, but to many others [close to the victim] as well.

In effect, the murderer is preparing himself for what would otherwise be a somewhat traumatic event. Murder can be traumatic. But if the murderer is sufficiently imbued with a sense of self, and a disconnected sense of self, then it’s less difficult. Of course, following the murder, this disconnectedness is what the world sees and sees immediately something is very wrong [because this person close to the victim doesn’t show the right emotion – because he’s disconnected himself…]

At 13:30 in the clip below, Forensic Psychologist Dr. Keith Ablow describes the mental process behind Scott Peterson’s less than credible acting.

ABLOW: I think Scott Peterson knows he is putting things over on people, or attempting to. The trouble is, because he can’t connect – he can’t feel your emotions, or his own [in terms of Laci] – he’s in a very tough spot as to lying effectively. But Scott Peterson thinks he’s very resourceful. No doubt he thinks people believe him when they don’t at all.