Describe some of the cultural and social causes of 'gendercide' why is there a preference for boys in particular cultures

Gendercide is the term by which girls are killed, aborted, or neglected in favor of male children, for reasons such as need for physical labor force of men, inheritance laws dictating male heirs, the fact females usually marry into another family and leave the family, or that you may have to pay a dowry for her marriage. In many families, this will result in abortion upon learning of the gender. 

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