Computational behavior theory and cultural evolution

Tag Archives: marriage

Video: Laura Fortunato, The Evolution of Marriage and Kinship Systems

Part of the Cultural Evolution Seminar Series at Brooklyn College

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Abstract: Kinship and marriage systems represent the ways in which humans organize relatedness and reproduction. The work presented in this talk extends the philosophical, theoretical, and methodological foundations of evolutionary biology to the study of these aspects of human social behavior. Specifically, I use game theory to show that the evolution of monogamous marriage can be understood based on inclusive fitness theory. Results show that where resources are transferred across generations, monogamous marriage can be advantageous if partitioning of resources among the offspring of multiple wives causes a depletion of their fitness value, and/or if females grant husbands higher fidelity in exchange for exclusive investment of resources in their offspring. I evaluate the results of the model using evidence about the history and cross-cultural distribution of marriage and inheritance strategies. This suggests that monogamous marriage may have emerged in Eurasia following the adoption of intensive agriculture, as ownership of land became critical to productive and reproductive success.

Laura Fortunato is Omidyar Fellow at the Santa Fe Institute. Her research investigates theevolution of human social organization, focusing on the social norms regulating kinship and marriage. This involves understanding (i) why societies differ withrespect to these norms – for example, why some prescribe monogamous marriage, while the majority allow polygyny; and (ii) how this variation came about – forexample, whether the prevalence of monogamous marriage among European societies is simply an artefact of history, or whether itreflects ecological and/or social determinants.

A Fine Example of Sexism in Italian Divorce Law

In italy, a woman cannot remarry until 300 days after a divorce. This norm intends to avoid paternity disputes by making sure that, upon remarrying, a woman is not expecting a child from her previous husband. Such intent is apparent from the provisions, stated in the same law, that allow to cut the 300 days short if:

  • The woman proves she is not pregnant.
  • The woman proves that she did not legally live with the former husband in the 300 days after divorce.
  • The previous marriage has been terminated because of the sterility of either partner.

How many flaws can you find in behind this norm? I have found the following:

  1. A divorcing man is not required to prove that his former wife is not pregnant, hence the norm is sexist.
  2. The law assumes that a woman has sex only with her husband.
  3. The law assumes that a woman has sex with a man only if they live together.

All this makes the norm ineffective in its intent, i.e., preventing paternity disputes. The law was written around 1980, mostly by men born in the 1920s and 1930s. Those aging, somewhat sexist, democratically elected lawmakers could not anticipate that paternity tests would obsolete their hard work in a few years. While point 1 above is, in theory, sufficient to make the law unconstitutional in Italy, the law itself has not, apparently, been challenged in court, and thus stands as of today, August 20th, 2009.

I have been able to find other similar cases: Puerto Rico, Lousiana before 1970 (remarriage laws in the U.S.). Do you know of other similar legislation elsewhere?