Segmentation is the oldest form of social organization. Human families, clans, and tribes have lived together for a few million years. Modern functional differentiation (global society split into functional subsystems of politics, law, economy, education, mass media, science, healthcare, sport, etc.) has obviously not eliminated families; however, functional differentiation now overrules segmentation. Evidence for this is that children and spouses or domestic partners are now afforded legal protection. Children and women can no longer be beaten with impunity. This means that the law (the legal function system) now overrules family segmentation.
Here is a quote from Herbert Spencer‘s Principles of Ethics:
That the law—Every man has freedom to do all that he wills, provided he infringes not the equal freedom of any other man—applies as much to the young as to the mature, becomes manifest on referring back to its origin. God wills human happiness; that happiness is attainable only through the medium of faculties; for the production of happiness those faculties must be exercised; the exercise of them pre-supposes liberty of action: these are the steps by which we find our way from the Divine will to the law of equal freedom. But the demonstration is fully as complete when used on behalf of the child, as when used on behalf of the man. The child’s happiness, too, is willed by the Deity; the child, too, has faculties to be exercised; the child, too, needs scope for the exercise of those faculties; the child therefore has claims to freedom—rights, as we call them—co-extensive with those of the adult. We cannot avoid this conclusion, if we would. Either we must reject the law altogether, or we must include under it both sexes and all ages.
Spencer, Herbert. The Complete Works of Herbert Spencer. Kindle Edition.
Below is a Google Ngram that shows when terms such as child abuse, child protection, child welfare, wife battering, and domestic violence first started to appear in books printed in English. Child welfare starts to appear in the early 20th century. The term child abuse first appears in about 1967. Domestic violence had been on the radar since the mid-19th century, but it only takes off after about 1976.