The authors investigate environmental reasons for cross-cultural variation in the permissibility of cousin marriages. In particular, they test whether higher levels of pathogen prevalence and geographic isolation increase the likelihood that cousin marriage will be allowed. The authors' underlying theory is that cousin marriages provide protective homozygosity against some pathogens and provide more options when mate choices are limited.

The authors investigate environmental reasons for cross-cultural variation in the permissibility of cousin marriages. In particular, they test whether higher levels of pathogen prevalence and geographic isolation increase the likelihood that cousin marriage will be allowed. The authors' underlying theory is that cousin marriages provide protective homozygosity against some pathogens and provide more options when mate choices are limited.

In order to evaluate an adaptive justification for restriction of ritualized physical contact, the authors test association between three manifestations of physical interaction and prevalence of pathogens cross-culturally. Their expectation, supported by two of the three tested hypotheses, is that higher pathogen prevalence will lead to customs of restricted physical contact. Both cultural and biological evolution are suggested to be influential in selecting for physically intimate behaviors.

The authors test the relationship between linguistic diversity and parasite richness, theorizing that anti-pathogen behaviors, such as the favoring of contact with a limited range of similar, nearby populations carrying the same suite of parasites and pathogens, will be selected for due to variability in immunobiological makeup between groups. As a result, cultural and gene pool isolation will be likely to further divide local parasite-host groups, generating language diversity as well as population divergence and new evolutionary forms among the parasites themselves. A significant positive correlation is found, which the authors suggest has important implications for future research regarding cross-cultural transmission and interaction.

This article uses factor analysis to identify the key variables underlying the many cross-cultural associations reported by Textor (1967). Twelve factors are identified.

This article explores whether the practice of cousin marriage helps explain the persistence of honor cultures and honor killings. The authors have hypothesized that cousin marriage can create kin benefits but also parent–offspring conflict, leading to the evolution of honor norms and punitive practices to enforce cousin marriages. Using genomic inbreeding coefficients as a proxy for historical cousin marriage across 52 ethnic groups, these practices are likely to enforce these marriages across regions within countries. The conclusion is that honor cultures may be rooted in kinship dynamics, particularly conflicts surrounding consanguineous marriage. Authors do raise evolutionary puzzle of why female victims are harmed by blood kin.

This article explores whether the practice of cousin marriage helps explain the persistence of honor cultures and honor killings. The authors have hypothesized that cousin marriage can create kin benefits but also parent–offspring conflict, leading to the evolution of honor norms and punitive practices to enforce cousin marriages. Using genomic inbreeding coefficients as a proxy for historical cousin marriage across 52 ethnic groups, these practices are likely to enforce these marriages across regions within countries. The conclusion is that honor cultures may be rooted in kinship dynamics, particularly conflicts surrounding consanguineous marriage. Authors do raise evolutionary puzzle of why female victims are harmed by blood kin.

In order to evaluate an adaptive justification for restriction of ritualized physical contact, the authors test association between three manifestations of physical interaction and prevalence of pathogens cross-culturally. Their expectation, supported by two of the three tested hypotheses, is that higher pathogen prevalence will lead to customs of restricted physical contact. Both cultural and biological evolution are suggested to be influential in selecting for physically intimate behaviors.

In order to evaluate an adaptive justification for restriction of ritualized physical contact, the authors test association between three manifestations of physical interaction and prevalence of pathogens cross-culturally. Their expectation, supported by two of the three tested hypotheses, is that higher pathogen prevalence will lead to customs of restricted physical contact. Both cultural and biological evolution are suggested to be influential in selecting for physically intimate behaviors.

The author analyzes the association between joking behavior and four types of instutionalized potential marriage relationships. Results show a tendency for a joking relationship to occur in all cases.