Interesting how this question was asked in the first place but the answer is revealing:
This paper tests the hypothesis that extended kin-groups, as characterized by a high level of cousin marriages, impact the proper functioning of formal institutions. Consistent with this hypothesis I find that countries with high cousin marriage rates exhibit a weak rule of law and are more likely autocratic.Democracy and a liberal society require family to be open not closed. If your culture deems family, and especially family honour as paramount and seeks to maintain family autonomy then you get more consanguineous marriage (with all the attendant issues). The authors here see how the ending of this pattern in Europe allowed strong non-family institutions including, in the end, democracy. This is a lesson that modern day Pakistan needs to learn:
Two months ago, a council of village elders ordered the rape of a 16-year-old girl, whose brother had been accused of raping a 12-year-old girl in Raja Ram village in central Pakistan. Shocking though it is, the case is no aberration. Revenge rape, honour killings, and the exchange of women are some of the routine ways through which disputes are resolved.
Far from outlawing these councils, Pakistan’s National Assembly shocked the country by seeking to give these councils quasi-judicial powers earlier this year. It passed a Bill providing legal and constitutional cover to jirga and panchayat systems, in an bid to ensure speedy resolution for “small civil matters” and free the formal judiciary of some of its burden.
....