We found that sharing & cooperation are necessary to survival. Nuclear family in this context would not be able to survive on its own. Don"t have a sense of private space live communally and collectively. Since the end of slavery in the us (1860s), there have been significant differences. After the 1940s; there have been lower percentages of marriage in the last few decades, the differences have been increasing. ***differences between african americans and the rest of the american population, only exist in the low income parts of the population** No significant differences between african americans and other americans in the middle class & upper class referring to low income categories. Much more likely than white americans to have kids outside of marriage involves race and poverty. *in the us -- over 1/2 of black babies born outside marriage, over half of babies living in lone-parent households; thus, a different pattern, for low-income african-americans.