Modern culture has buried the biological origin of social behavior: why?

Modern culture has buried the biological origin of social behavior. Think of that: buried. There is virtually no mention of it in political philosophy today.

Yes, there is a co-evolution between biology and culture, but “biology is the hardware, culture is the software.” We don't even hear that mentioned much and it certainly doesn't condone burying biology in the glut of freaked out cultural software.

So why has the biological origin of social behavior been buried? Mainly because it is thought to not enhance the biological and social power of those who bury it for that reason.

The fascists affirmed the biological origin of social behavior but then they demeaned it by including crude supremacist values for only one chosen people. World War Two ended 74 years ago but the Big Media and the schools today make it look like the fascists were defeated yesterday and could rise at any minute. That is resentment toward a defeated foe on a grand but degenerate level, and unworthy of a noble people.

Modern culture and modern trends reek of an entirely fictionalized view of human nature that buries real human nature as the will power of those who bury it. Human nature  remains as it has always been: genetically kin-centered, gender defined, age-graded, heterosexual, marriage-making, hierarchical, ethnocentric, even xenophobic, and religious-making, among other things, with group-selection as the primary unit of successful selection, followed by individual selection.