Within Part Three of the book, Chapter 14 is the only one that deals with issues of societal and political structure. In that chapter, Diamond describes four types of societies. The lower two might be called collectivists while the higher two might be called individualists. (Diamond does not use these terms, but we can infer them from what he says about these societal types.
To Diamond, both bands and tribes are collectivist. He points out (for example in Table 14.1) that these are societies that are not stratified. He says that land is owned collectively in these types of societies, either by the whole band (in bands) or by clans (in tribal societies). Decision making is egalitarian and there is no hierarchy in their settlements. All of these things add up to what we might call collectivism.
We must then ask what factors having to do with agriculture determine which societies end up as bands and tribes and which become larger. Diamond says that any time a regional population is large, it is likely to form a society of the larger two types. He argues that populations will become large whenever there are sufficient resources to allow for relatively intensive agriculture.
Reading Chapter 14, then, we can at least infer that the level of resources is what makes some societies individualist and some collectivist. A society like the Fayu, living in swamps where agriculture is not even possible, becomes a society of bands. A society like that of Hawaii has many more resources and becomes a chiefdom.