More than half of the respondents to a recent New York Times/CBS News poll of 708 unemployed adults nationwide said they had borrowed money from friends or relatives. In most cases, their financial pictures were bleak. Nearly 80 percent of those who reported borrowing money said their family’s financial situation was “fairly bad” or “very bad,” a significantly greater proportion than among those who had not had to borrow.
The numbers here might exaggerate the effect some, as an individual who is going through financial turmoil may assess the world more darkly than one who isn’t. That being said, it is pretty obvious that income is not randomly distributed across familial networks, and those with resources who are less likely to require aid are actually the ones who will have family in a position to offer it if needful. By contrast, those on the margins are the most likely to have family on the margins.
In pre-modern societies this likely explains how inequality across lineages becomes amplified. Families with more buffer on the margin are less likely to become dispossessed through inclement shocks, and can use their surplus to acquire the property of those lineages which have become impoverished.
This is why economic growth and gains in productivity are essential. In a Malthusian world the way that a high tension state of high inequality eventually “corrected” itself was for massive institutional collapse and general chaos to level the playing field. Of course, the playing field was far more barbarous than it had been previously, so there was probably a trade off between cultural creativity and equality.