It is the duty of a dead mans brother to marry his brothers widowed wife.
Saltah told me that this was the custom in Kazakhstan in the past. When I asked if it still happens, she told me that it is not usual, but it does still sometimes happen. Also, she added that men used to marry multiple wives in Kazakhstanas long as they could afford to support them all. Although this is not legal anymore, Saltah said she heard of instances where people do this anyway. According to her, the wives say that as long as they are comfortably supported and given separate houses, they are fine with the traditional arrangement.
I think that these traditions together show a much more traditional attitude toward marriage, as opposed to the contemporary associations of marriage and love. Rather than a vehicle for love, these customs seem to view marriage as partnerships to ensure financial and filial stability. The traditional gender roles are clearly emphasized over any notion of love. The duty of a husband is not to love his wife, but to food on the table. A sympathetic brother would want to make sure his brothers wife is well taken care of; under these understandings of marriage, to marry the widow would be an ideal way to provide for her. Because there is little association between marriage and love, this does not bring about issues of jealousy the way a comparable relationship might in the US. This would also explain why the multiple wives did not mind the polygamy. Loyalty and affection are secondary, perhaps of little meaning to them. As long as the husband can fulfill his duty as breadwinner for all of the wives, they are satisfied. And because he can fulfill his duties as a husband to a greater degree than most men, it would make sense that he should receive a higher than average proportion of benefits afforded by the wives traditional role: more offspring.