In earlier periods women's  were locked in home itself. Because in earlier periods only men's are fixed for all works but the women's were fixed  only for cooking, house works, and also most of them and thier thought was not to dominate the society and men's . we can't change in earlier generation but we can change in the upcoming generation but there should be control and restrictions. bcs parents wants their child in good manner, so oly some parents doin this but most of all we didnt understand them well
I think this is all because of the traditional mindset that men are the breadwinners and women are the caretakers. Boys and girls are allotted different roles and are expected to behave accordingly.  
Parents also often neglect girls because they think of them as a burden. They think that they have to be taken care off and then she goes elsewhere after marrying. Dowry system is an addition to their misery.
We should not look upon to boys as superior to girls. They both should be treated equally. Dowry system and killing girl child should be stopped.