In Guns, Germs, and Steel, the theme of domestication is central to understanding the development of human societies. Jared Diamond explores why certain societies advanced faster than others, attributing much of this to the domestication of plants and animals. He argues that the ability to domesticate species was largely due to geographical factors rather than cultural or racial superiority. This domestication provided societies with stable food sources, labor, and other resources, which in turn supported the growth of complex civilizations.

Diamond identifies six main characteristics necessary for successful animal domestication: the ability to breed in captivity, quick growth, docility, a social or herd structure, a flexible and efficient diet, and calmness. These traits make animals manageable and cost-effective to raise. For example, animals that breed easily in captivity and grow quickly are more valuable for food production. Similarly, animals with a calm disposition and social structures are easier to manage in groups, making them suitable for domestication.

"The Anna Karenina principle explains a feature of animal domestication that had heavy consequences for human history, namely that so many seemingly suitable wild mammal species, such as zebras and peccaries have never been domesticated." (Diamond)

The Anna Karenina Principle, as used by Diamond, explains why many animals were not domesticated. According to this principle, just as a happy marriage requires several factors to be successful, domestication requires multiple conditions to be met. If any one factor is missing, domestication fails. This principle highlights why some societies could not domesticate certain animals, not due to cultural failings but because the animals lacked the necessary traits.

Diamond also addresses the late domestication of American apples, using it to illustrate the role of necessity and available resources in domestication. He suggests that while Native North Americans could have domesticated apples, they did not feel the need due to abundant wild resources. This example underscores his argument that domestication often depends on the perceived necessity and available technology, rather than a lack of ability or interest.

Overall, Diamond refutes the idea that cultural differences led to the failure to domesticate certain animals. He argues that geographical luck determined the availability of domesticable species. Societies in regions with suitable animals could advance more rapidly, while those without such animals could not, regardless of their cultural practices. This perspective shifts the focus from cultural superiority to environmental factors in explaining historical development.