This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

This article considers the consequences of modernization. Factor analysis is used to identify four stages of modernization: 1) changes in education, government, and trade; 2) changes in health, technology, and transportation; 3) changes in family, religion, and toilet; and 4) changes in behavior. The authors then consider five trends they expect to be associated with modernization and test whether they develop over the course of the four stages. Results indicate that these 5 trends—increased cultural complexity, female status, pacification, suicide, and social stress—are associated with only the first and fourth stages.

This article considers the consequences of modernization. Factor analysis is used to identify four stages of modernization: 1) changes in education, government, and trade; 2) changes in health, technology, and transportation; 3) changes in family, religion, and toilet; and 4) changes in behavior. The authors then consider five trends they expect to be associated with modernization and test whether they develop over the course of the four stages. Results indicate that these 5 trends—increased cultural complexity, female status, pacification, suicide, and social stress—are associated with only the first and fourth stages.