I recently ran into an interesting description of the Ik people in Tainter's Collapse of Complex Societies (copy):

"The Ik are a people of northern Uganda who live at what must surely be the extreme of deprivation and disaster. A largely hunting and gathering people who have in recent times practiced some crop planting, the Ik are not classifiable as a complex society in the sense of Chapter 2. They are, nonetheless, a morbidly fascinating case of collapse in which a former, low level of social complexity has essentially disappeared.

Due to drought and disruption by national boundaries of the traditional cycle of movement, the Ik live in such a food- and water-scarce environment that there is absolutely no advantage to reciprocity and social sharing. The Ik, in consequence, display almost nothing of what could be considered societal organization. They are so highly fragmented that most activities, especially subsistence, are pursued individually. Each Ik will spend days or weeks on his or her own, searching for food and water. Sharing is virtually nonexistent. Two siblings or other kin can live I side-by-side, one dying of starvation and the other well nourished, without the latter giving the slightest assistance to the other. The family as asocial unit has become dysfunctional. Even conjugal pairs don't form a cooperative unit except for a few specific purposes. Their motivation for marriage or cohabitation is that one person can't build a house alone. The members of a conjugal pair forage alone, and do not share food. Indeed, their foraging is so independent that if both members happen to be at their residence together it is by accident.

Each conjugal compound is stockaded against the others. Several compounds together form a village, but this is a largely meaningless occurrence. Villages have no political functions or organization, not even a central meeting place.

Children are minimally cared for by their mothers until age three, and then are put out to fend for themselves. This separation is absolute. By age three they are expected to find their own food and shelter, and those that survive do provide for themselves. Children band into age-sets for protection, since adults will steal a child's food whenever possible. No food sharing occurs within an age-set. Groups of children will forage in agricultural fields, which scares off birds and baboons. This is often given as the reason for having children.

Although little is known about how the Ik got to their present situation, there are some indications of former organizational patterns. They possess clan names, although today these have no structural significance. They live in villages, but these no longer have any political meaning. The traditional authority structure of family, lineage, and clan leaders has been progressively weakened. It appears that a former level of organization has simply been abandoned by the Ik as unprofitable and unsuitable in their present distress (Turnbull 1978)."

From Wikipedia:

Children by age three are at least sometimes permanently expelled from the household and form groups called age-bands consisting of those within the same age group. The 'Junior Group' consists of children from the ages of three to eight and the 'Senior Group' consists of those between eight and thirteen. No adults look after the children, who teach each other the basics of survival. However, it is not certain whether this practice is typical Ik tradition or merely triggered by unusual famine conditions.

...Turnbull clearly became very involved with the Ik people, and openly writes about his horror at many of the events he witnessed, most notably total disregard for familial bonds leading to the death of children and the elderly by starvation. He does speak warmly about certain Ik, and describes his "misguided" efforts to give food and water to those too weak to provide for themselves, standing guard over them to prevent others from stealing the food. Turnbull shares these experiences to raise questions concerning basic human nature, and makes constant reference to "goodness" and "virtue" being cast aside when there is nothing left but a need to survive (even going so far as to draw parallels to the individualism of 'civilized' society). Overall, living with the Ik seems to have afflicted Turnbull more with melancholy and depression than anger, and he dedicated his work "to the Ik, whom I learned not to hate".

On the other hand: http://en.wikipedia.org/wiki/Ik_people#Criticism_of_Turnbull.27s_work