Institutions as in what? For openers, the institutions of religion, a traditional western marriage, and the Have and Have Not horror (which in essence is a profoundly conditioned social structure).
To take the second one first, I suspect there is nothing humans represses more than that "marriage" (especially monogamous marriage) is merely a relative social institution. It's not in any sense biologically hard wired into our species and in spite of all the legal and religious jazz, it is a completely arbitrary social construction.
But for many (most?) of us, it is the God of our lives. But why should that be? Why should this concatenation of "rules" kill our individuality?
Hey, we're the dogs, not the tails, but we certainly don't live like that. When you pass through a marriage abracadabra ritual, you have surrendered the "center of gravity" of your life to what is a social "game", but a game backed up (rather like gold backs up paper money) by OTHER institutions, such as religion and a bunch of dreamed up "laws".
Probably nothing in life is a better example of the infinite stupidity of being a jail cell (often for the rest of your life) with one wall wide open. Yes, there are "consequences" when you get a divorce, but the MAIN thing that keeps probably most of us playing the game is we don't think it IS a game -- even though it's hard to say just how we do think of it.
Obviously, for some of us it's a commandment straight from God (whatever that means). For others, perhaps less religious, it has massive cultural "weight" that chains us to a defined way of life.
In either case, however, these are both simply forms of profoundly successful social conditioning.
It's easy to write off such of critique of marriage as sour grapes or "atheist thinking", but such responses beg the question since they are merely variations of not wanting to face the truth of things. And the truth of things is that institutional marriage is a "passing fancy" of evolution and will almost certainly be selected out in the relatively near future.