In Conscience and Courage, Eva Fogelman writes "It was not a whim that lead these people to risk their lives and those of their families, but a response, almost a reflexive action in some cases, that came from core values developed and instilled in them in childhood." (1)
Holocaust rescuers were raised in families that provided a nurturing environment. The children developed a sense of self-worth and the ability to care for others. The care the rescuers received became part of their character, an integral part of the way they functioned in society.
When we know how to look, we will see continuous causality functioning all around us. A cause has a result, which in turn becomes another cause with another result, anther cause, another result, and on and on it goes. In this case, children had the causes and conditions to be born into a loving, nurturing family. This care resulted in their becoming people who risked their lives to do what they knew was right.
Good values result in virtuous actions. Causality at it's finest.
(1) Conscience and Courage, Eva Fogelman, Anchor, p. 253