Chapter 9 - Zebras, Unhappy Marriages, and the Anna Karenina Principle

In “Zebras, Unhappy Marriages, and the Anna Karenina Principle”, Diamond expresses that Eurasian peoples ability to domesticate 13 of the “Ancient fourteen” wild ancestors of today’s domesticated animals led to their gain of guns, germs and steel. Diamond explains how Eurasian peoples success in domesticating animals is not because of a cultural differences. Rather their success is a result of their geography and the Anna Karina Principle. 

Firstly, Eurasia had the most big mammal “candidates” for domestication due to there large landmass and very diverse ecology. Additionally, Eurasia and African loss least amount of candidates in the late Pleistocene wave of extinction. Unlike the Americas and Australia, who lost the most. After these two factors considered, Eurasia had 72 candiates. This is compared to sub-Saharan Africa with 51, the Americas with 24 and Australia with 1.  From here, the actual domestication of these animals is dependent on the Anna Karenina Principle. 

Paraphrased by Diamond the Anna Karenina Principle states the happiness of marriage dependents on the fulfillment of many criteria. If one of those respects is not achieved, the marriage will be unhappy (despite any factors that lead to happiness).  The same applies the domestication of animals.  In order to domesticate a big mammal they must have the proper diet, growth rate, matting habits, a lack of disposition to kill or injure human, a lack of a tendency to panic, and social structure. If any of these are satisfied it will be an unfit marriage for domestication. Thirteen of or the 72 candidates in Eurasia satisfied all of these respects, 1 candidate did elsewhere. 

An explanation of each of these principles is as follows: 

Growth Rate: “To be worth keeping, domesticates must also grow quickly” (163). 

Matting Habits: If an animal will mate in captivity 

Nasty Disposition: A tendency to Kill humans

Tendency to Panic: If an animal has a tendency to panic in confined spaces it will not be fit domestication. 

Social Structure:  Big mammals that travel in herds and have a social hierarchy are ideal for domestication. As humans take over they will follow the human as their leader replacement. They are instantly submissive. Furthermore, herds typically tolerate each other, while solitary territorial species do not.