I mostly concur with homerjsinnott.
The vast majority of Broo are feral - born in the wild to some random mother that was impregnated by a passing Broo, who was also probably feral. They are kiley to be born near loose wild communities of other Broo, and band together. They have little in the way of a society because they have no tradition of nurturing and rearing because the mothers are always unwilling and often die during childbirth. They may learn some basic survivial skills and rudimentary magic from other Broo in the band they join.
Even in more organised groups, their society is very rudimentary, again due to the lack of a nurturing and educational phase in childhood, and the brutal nature of what passes for culture. The first act of any newborn broo is usualy to kill and devour it's mother as they eat their way out of his or her body, and I expect they are probably self-aware at that stage. I don't think the sources say as much, but I think many broo actualy remember this stage in their life into adulthood. For Broo, love is a unimaginable concept.
Broo are dominated by their sexual urges, which are much more powerful than those in the most randy humans, even ones with abnromal metabolisms. Even educated and clever Broo will find it difficult to put aside their rutting instincts for long, and frankly why should they? In their mythology, their mother goddes was raped and abused and denied justice by the gods who essentialy blamed her for the whole thing. They believe that the world is fundamentaly immoral and all the gods are corrupt and evil, only presenting a facade of respectability. The created world is doomed by Chaos, which is a weapon of vengeance against a cosmos that hates and fears them.
Simon Hibbs