If you know you are incompetent, why try to fix a broken arm? Because you might be a sociopath or psychopath--officially known as antisocial personality disorder. And while psychopaths can be calculating, that doesn't mean they are smart or that they are typically violent.
Recent research suggests a psychopath’s brain is not like other
people’s. It may have physical differences that make it hard for the
person to identify with someone else’s distress.
The differences can even change basic body functions. For example,
when most people see blood or violence in a movie, their hearts beat
faster, their breathing quickens, and their palms get sweaty.
A psychopath has the opposite reaction. He gets calmer. Kipnis says
that quality helps psychopaths be fearless and engage in risky
“They don’t fear the consequences of their actions,” he says. FROM WEB MD
There are plenty of real life instances where someone who is pretending to be an expert goes ahead and tries to be, sometimes to disastrous results. In Miami in the 1980s there was a pediatrician who actually wasn't a doctor at all. He knew that. And yet, he treated patients, (I was one of them) sometimes with serious illnesses. This has happened over and over again in real life. Do you know the reason that hospitals vet doctors before allowing them to do surgery? It's because people who aren't doctors WILL try to perform surgery.
Lockhart is what's known in the biz as a bullsh*t artist. The biz being con artistry.
He has established a pretty good pattern, which actually tracks as far as these types of criminals--when his lack of competence puts someone else in danger, he's more than happy to keep on with the bluff. He's been doing this for so long, that basically he knows he can talk his way out of anything. BUT, when his lack of competence might put HIM in danger, he tries to get out of it (he's packs to leave when forced to actually face danger/his own incompetence).
This points to a self-centeredness and lack of empathy. Basically, if it happens to work, he can coast on it for a while. If it doesn't, well, there's a nurse right on the grounds, isn't there?
A sociopath has a weak conscience, a psychopath doesn't have any at all, and they tend to engage in risky behavior, escalating as time goes by. I think that psychopath is more of a fit for Gilderoy. He has zero remorse concerning Harry's arm, in rearranging people's memories and stealing their lives, and in erasing the memories of children. I know that in popular literature and movies that a psychopath is generally violent, but that's simply not true. He's got it all--the superficial charm, the reckless risk-taking, the calculation, pathological lying...
Pretty much, bottom line, psychopath or sociopath, there is definitely something missing from Gilderoy in the empathy department.