The hundreds of murders of Palestinian Arabs by other Palestinian Arabs that I have been documenting for the past six months is nothing new. A very similar situation occurred from 1936-39.
The Arabs of Palestine tried on a few occasions in the 1920s and 1930s to rise up and destroy the Jews of Palestine, and things were very bad in 1936. Yet no matter what they did, the Jewish influence on the area kept increasing, Jews kept arriving and Jewish institutions thrived.
They then started killing each other in earnest. I'm not sure why - perhaps it was frustration at their impotence, perhaps because an entire generation had been raised to praise Arab murderers as heroes and therefore bloodshed itself became considered desirable, or maybe they simply started misplacing their hatred for Jews and the British onto any Arab that was too Western for their tastes. Nationalism and religion seems to have played a part but more as excuses rather than as root causes.
Either way, the amount of lawlessness that ensued looks very familiar to those of us who have been following "clan clashes" and the Fatah/Hamas civil war. Especially notice how many Arabs were killed for not wanting to join in with the terrorists, or for speaking out against the terrorists. Also note the left column, dealing only with the terror crimes of the previous day.
There are three more columns of dead Arab victims of Arab violence I didn't reproduce.
Whatever psychological reason one wants to hypothesize, one thing is the same then as now: the most extreme elements of Arab society are not dealt with adequately by more moderate Arabs (either out of fear or out of ideology.) This apathy is treated as carte blanche to accelerate the terror.
This could explain why so many Arab societies are either chaotic messes or autocratic dictatorships. There seems to be no real internal mechanism within Islam or Arab thinking to limit the influence of the terrorists, so either go the route of Egypt/Syria and repress everybody, or go the route of the PA and Somalia and let the foxes run the henhouse.