One major change brought about by the status-striving phase of the economic cycle is intensified sibling rivalry. It's "just another" form of hyper-competitiveness, but one that threatens a core institution which is supposed to be beyond the effects of economic cycles.
No matter when you observe them, Baby Boomers have basically gotten along with their generation-mates within their kin groups -- siblings, cousins, and so on. And of course they got along with their parents, aunts and uncles, etc. Their bonds with these individuals were formed during the accommodating phase of the cycle, up through the 1960s and even into the '70s, which were a transition ("Me Generation") between the New Deal / Great Society era and the Reagan Revolution.
They do rib each other here and there, engage in "a little friendly competition" over inane crap, but overall the roots show from the pre-striver era, and they get along with one another.
The quality of these interactions takes a noticeable drop with Gen X, and really flatlines once the Millennials become involved.
For Gen X, relationships with cousins are distant and awkward, though well-meaning rather than hostile. Similar well-meaning awkwardness among siblings. They reflect the lack of time that X-ers made for others during their proto-careerist adolescence. As with any secular trend, it's worse for the later than the earlier members.
For Millennials (who in this context appear to begin with 1982 births), family gatherings bring out only aggressive egocentrism. They're rehashing what is familiar from their upbringing during the era of high-stakes childhood, especially since the 1990s. In well-adjusted families, this constant status-jockeying may appear less hostile, while in dysfunctional families it will take the form of endless sniping and baiting.
It's not the cathartic "getting it all out there" kind of battle within the family. That has an end goal -- clearing some kind of emotional clog in the system -- which once reached, brings satiety to the participants, who go back to normal for awhile. The oneupsmanship over the most petty shit has no goal other than to draw out the contest into another round. Without any satisfaction to resolve the drama, the gathering ends abruptly and awkwardly with the tension still hanging around undissipated.
These generational differences have been stable, from what I've seen of my family's home movies, at least back to the 1960s. Little Boomers weren't tearing each other to shreds back then, and do not do so now. Once you see home movies from the '80s, it's apparent how even as small children the X-ers and later the Millennials would move family gatherings step by step closer to sibling rivalry death matches.
At this point, it's no longer possible to believe that we will change things directly, and drop our hyper-competitiveness with our siblings. The best we can do is try altering the social climate toward one of accommodation rather than me-first. Making public displays of being sick and fed up with steel cage matches over nothing could at least signal to the next generation that they'd better not continue the practice. Pre-emptive shunning of social behavior that poisons the family.
Getting that message across broadly will probably take another generation or two, but it's happened before, so it can and will happen again.