Sunstone said:
Is Judaism intrinsically more humanistic than Christianity and/or Islam? If so, why? If not, why not?
No, definitely not. Not intrinsically. Judaism at its worst can be just as blind, just as intolerant, just as violent as Christianity and Islam at their worst. I'm thinking of Meir Kahane and Kach, but you could list other examples.
But in practice Judaism, at least in the West, often does tend to be more humanistic than its sisters. I can think of a couple possible reasons. The strong Jewish tradition of study and education -- which leads to more disciplined thinking and has also led many Jews to excel in secular education -- and the long Jewish history of persecution. Persecution can warp you and make you cruel -- and we see that sometimes in Jewish people -- but alternately it can make you compassionate towards others, and we see that, too.
At present, the one great blind spot of the Jewish people is their refusal to face up to Israel's treatment of the Palestinians. I won't take this thread as an invitation to rant on that subject, but the significance of it shouldn't be underrated.