In evolutionary terms, niche construction has a specific meaning. It's the modification of the environment that elicits an evolutionary response. Still, environmental alternation alone is insufficient. In the human context, environmental changes must be coupled with cultural adaptations to achieve an evolutionary response, a gene change.
Since the 1960s, this dynamic has laid the foundation for a revised conception of evolution, where genes and culture persistently act together in a feedback loop––alteration in culture influences natural selection that then modifies genes, and vice versa, alteration in genes influences natural selection that then modify culture.
The Colorful Prince’s proposed cultural adaptation, skinship, is a 'socially learned behavior' where kinship is based on proximity, shared circumstances, living together, sleeping with each other, working together, and sharing food. 'Culture,' in this context, coupled with niche construction and behaviors observed, copied, and taught by family members, is meant to co-direct evolutionary change toward altruism.
What appears to be random reciprocity and sexual freedom for both men and women is selective pressure at work within a given population without regard for "blood ties" or social and economic status. The close contact and touching within the cultural niche provide a reliable setting that allows selective pressure to develop and drive natural selection.
However, intentional niche construction and gene-culture coevolution are not to be mistakenly confused with Eugenics, practices that aim to improve the genetic quality of a human population by selective breeding or artificial selection––excluding people and groups judged to be inferior or promoting those judged to be superior––gene-culture coevolution moves in the opposite direction toward Human Inclusive Fitness.