What probability did mankind have to overcome to evolve as an intelligent species?

Equal ways and means in living the life for the love in all people, places, and things, that is created equally for the purpose we are created to have it this way.

Until then...some people will try and keep fooling other's into thinking they are smarter, and take over what they have, keeping all on an unequal ways and means, and this is an evil way, by those who do it. By destroying that way, it will elimate those in being able to do it, because they will have to settle for equal, or not at all will they survive it, by their own choice in the matter.

The law is made possible by the Golden Rule, by God, that we are given this within, and unanimously agreed upon within the constitution of all equally. It's there, whether or not some people tell it, or keep it a secret, with words unspoken.

It isn't always easy, only possible..and not always as difficult, probably the way. It will take handling it moderately for it to happen, and that is the good way, for those who do.

Large craniums make childbirth dangerous. In addition, they are nutrient hungry. There has to be a pay off in natural selection. In the case of our lineage, the larger brains that enabled our cognitive abilities must have given enough advantage to pay off the danger.

100%... it happened.