Bands have no permanent single base of residence, instead land is used jointly by the whole group, as opposed to being partitioned among subgroups or individuals. There is no regular economic specialization, except by age and sex: all able-bodied individuals forage for food. There are no formal institutions, such as laws, police, and treaties, to resolve conflicts within and between bands. Organization is often described as "egalitarian" in the sense that there is no formalized social stratification into upper and lower classes, no formalized or hereditary leadership, and no formalized monopolies of information and decision making. However, this definition of egalitarian should not be taken to mean that there is equality in prestige and the decision-making process among band members. Instead "leadership" should be thought of as informal and acquired through qualities such as personality, strength, intelligence, and fighting skills.