madam the thing is u have only taken one aspect "of the society and the role of women"... the topic for which you seek a satisfactory answer lies in the individual's mind set. like for example, i have never ever thought that my elder sister has lesser rights than me or my elder brother. Actually this problem has its roots in the mindset of parents and moral education provided by them to their children.
"HAM VAHI KAT TE HAI JO HAMNE BOYA HAI"... not every family discriminates daughters this u should understand.[ And this problem can not be solved with the snap of a finger we have to take the initiative "each one of us" we will have to teach our children to respect women and their rights equally as we respect our own.] i think this is the answer you should give to your younger brother and guide him towards the correct form of moral education which our traditional parents are ashamed to provide to their children.

just give your younger brother the quotes of MK Gandhi over this topic- "Be The Change you despirately want in others" then only we can make this world a better place for both the genders.