Chapters 7-9


The mixed economy of hunter-gatherers became a way of life. It is a system that dominated life for at least two million years before the advent of agriculture. Even today, some tribes around the world still participate in this practice, and interestingly enough, have significantly more leisure time, proving a misconception about this way of life wrong. The network that holds these groups together is kinship, and the primary observed behaviors are sharing and cooperation. The Kung people are one example of this type of system.

There are complicated social structures in these groups, with many complicated rules surrounding marriage and other social activities. These structures depend on the specific group being discussed. One thing is for certain: this way of life is nowhere near as primitive or brutish as often described, even by great philosophers such as Thomas Hobbes. Socially, one thing in common across all forms of society is the taboo of incest, and this is no different in hunter-gatherer communities. Leakey and Lewin describe it as “a biological imperative packaged in a social custom”. Another social custom that is prevalent is the focus on meat, as it serves both as nutrition and a means of social interaction, which can be seen across a number of different primates. As one can expect, there are strict social rules when it comes to the consumption of meat, as well.

The authors continue to go back to the Kung way of life as being representative of hunter-gatherer societies as a whole. They specifically mention that one can not judge the complexity of people’s minds by awarding prizes for the sophistication of tools used. They write this so as to defend against the idea that this is a “primitive” way of life, when it is actually extremely effective and allows these people to live the life they want. While the Kung may not be able to explain some of their behaviors as well as others, they are just as accomplished naturalists when it comes to interaction with the environment around them. It can perhaps be argued that they are even more effective when it comes to the amount of energy investment they use in order to sustain themselves.


This chapter introduces the idea of the “Hunting Hypothesis”, that states that is was only when our ancestors took up hunting that we began to become more human-like. Supporters of this argument claim that the intellectual skills demanded by organizing excursions such as these propelled us into our unparalleled evolutionary position. On the other hand, there is an idea introduced called the gathering hypothesis. This is based on the idea of the mixed economy that was previously described, and explains how hominids were able to better exploit the environment in which they lived better than their australopithicene cousins.

The separately organized collections of animal and plant food gave our ancestors a greater share of the resources available, and the concept of sharing food helped to further this. Moreover, plant food has always dominated the diets of human ancestors. Meat gradually became more and more prevalent as time went on, but it is safe to assume that early Homo would have only tasted flesh once in a while.

Leakey and Lewin also dismiss the idea that hunting was the cause of upright walking, explaining away a number of misconceptions about walking on two legs being seen as more beneficial with no basis. They also mention that earlier in history, it is likely that they were more of “hominid scavengers” than full-blown hunters. The mixed economy that persisted allowed for a division of labor and greater efficiency, which then allowed for more leisure time, as seen in the Kung today.

This “affluent society” would have had a number of other items to make life easier, including basic tools, carrying containers, and crude spears that would have made this reciprocal food-sharing economy so effective. It is this sharing and the honored network of obligation that developed that makes us uniquely human today.


The topic covered in this chapter is widely debated, as is the concept of when our ancestors became, what we call, “intelligent”. The brain is obviously the focus when it comes to this conversation, with the three important characteristics being size, shape, and the network of nerve fibers. Therefore, brain size alone cannot be a foolproof indication of intelligence. Even so, there are significant differences in the brains of Homo and Australopithecus. This means that whatever shaped the hominid brain into its modern form was likely at work all the way back in the Miocene.

The crucial factor when it comes to brain size is not volume, but rather size relative to the body. Among the apes, humans are most generously endowed. Since other early hominids would have had similar brain sizes, the brain that separated us from those like 1470 must have also had increased internal complexity. It is this factor that is most important to determining intelligence, according to the book. Unfortunately for anthropologists, this is also the most difficult factor to measure because it does not show up in the fossil record.

Some of the things that are looked at in determining intelligence are the following: language, self-awareness, and death awareness. These separate humans from almost all other species, and may have been what led our ancestor to be best prepared for evolution. Humans are also the only animals that use tools to make other tools. Whereas chimps have to be intelligent for social reasons, evolution has determined that humans and our ancestors had to be intelligent for technological reasons as well. It was these social and technological factors that helped pressure the higher primates and ourselves into developing what is now called “intelligence”.