What point is Huxley making about human nature and the nature of human communities?
In Brave New World, Huxley is satirizing how an extreme governmental and technological "community" has destroyed human individuality, the family, education, religion, and human correspondence with nature through the following ways:
The government controls technology to control us. Humans are no longer born in Brave New World; they are decanted. Science and technology have been used by the state to replace natural reproduction. Birth control is mandatory. Drugs are part of religious observance. In these ways, technology controls humans, not humans controlling technology. Huxley warns us of an over-reliance and faith in science at the cost of human values, especially in the areas of human reproduction and family planning.
Communist government and doctrine control and destroy the individual. There is one world state in the novel, and the World Controller preaches the mottoes of communism and socialism ("identity, community, stability"), eerily reminiscent of Soviet Union doctrine. John, the symbol for individuality, kills himself at the end because he has no more fixed identity; he has become "we," a slave to the group. Huxely warns that a community must make room for the individual, especially a rebel (like John).
We have become a nation of pleasure-seekers. The citizens of the Brave New World have no private shame or monogamous values; instead, they are encourage to share their bodies openly with multiple partners, to engage in "orgy-porgy," to watch "feelies" incessantly, and to equate religious observance with drugs and free love. In this way, Huxley presages our addiction to mass media (TV, movies, Internet) carnality at the sake of religious and family values and tradition. We have become a "me-first" nation that is ruled by pagan idolatry, whether it be shopping, porn, reality TV, or food. We must have it all to excess.
Huxley illustrates that we as individuals are formed by the communities into which we are born. In other words, for him, it is nurture, not nature, that makes us what we are. Even in the World State, where individuals are genetically engineered, it takes years of intensive and continuing conditioning to create model citizens.
The differences between John the Savage and his mother, Linda, show the effects of social conditioning most starkly. There's scarcely a closer genetic relationship than a mother and her child, but John and Linda couldn't be more different. Linda wants nothing more than the cleanliness, superficiality, and comfort of "civilization." She never adjusts to life on the Savage reservation. John, in contrast, formed by the values of the reservation and his reading of Shakespeare, finds it ultimately impossible to reconcile himself to life in his mother's world when they both end up in the World State.
As for the nature of human communities, Huxley shows through both the World State and the Savage reservation that communities are brutal in forming their people. In the World State, babies are subjected to electric shocks for conditioning. On the Savage reservation, beatings are part of religious ceremonies as well as a way to enforce social norms. Linda, for example, is beaten by the women for being a "whore," though she has no context for understanding what that means. It's brutal force that holds people together as a group, Huxley seems to say. For him, there is no ideal human society.