There is hardly any merit going to grandfathers because even though many of them show fondness for grandchildren, the plain truth is that they are not as nurturing as grandmothers.

Most men are deadbeat Dads, meaning that they are good for nothing but performing sexual acts which result in progeny. That does not mean that it is their fault, because after all maybe they are not endowed with the required nurturing tendencies as women are.

But a man can think it out and induce himself to contribute. That is possible. There is enough evidence to support that idea in a handful of males.