Because of their intense interest in the field of psychology there is no way you would ever find objective studies on the matter. I dont know if they are more psychopathic across the board, but the most influential and ethnocentric among them seem to be. It's no coincidence so many of the worst "me too" examples were powerful Jews(most of whom were lefties). They were heavily involved in organized crime in the 20th century. The famous Murder Incorporated was largely a Jewish run operation. Plus you have the mass murder and torture carried out by Jewish Bolsheviks during and after the red terror. It's often been stated that wall street is full of literal sociopaths. It would also help explain why they were expelled from so many communities and nations. Sociopaths inevitably wear out their welcome.

Even the way things went down in ww2 points to a high level of sociopathy among their elite, who escaped the Nazis early on and then urged the allies to wage total war on Germany despite the fact huge numbers of Jews were still trapped in Nazi occupied areas and the Nazis had explicitly warned they would retaliate against them. Their elite viewed them as expendable, then later used their deaths to advance their agenda and increase their power. Sounds pretty sociopathic to me.

Most damning of all is the fact they never seem to express collective guilt or remorse about anything while demanding collective guilt for whites. They are always the victims. Always blameless. The saying about crying out in pain as they strike you is classic sociopathic behavior.