Parental Roles:

Mom: She is like the boss of the family, because she trys to control all, everything that someone in the family buys, they decide who makes something in the house, because if you dont let her make evetything they want, they do a " drama" .
Dad: Normally, he is the people, that bring the money and the things in the house, he works and sometimes his wife controls him, well thats a "mandilon" people , also he can be the boss, but if he is the boss is dangerous because normally when a dad controls the family is more like a "macho".
First born child: He is the boss of the other children because he/she controls because is bigger or taller or stronger, also is the example for the other children, because if he/she makes something bad the other children are going to copy it.
Sandwich: Is like the "olvidado" or something like that, because all the family pay more attention to the older or to the younger, the sandwich can not exist and maybe the family dont pay alot of attention.
Youngest: It can be the favorite of their parents because is the youngest and he/she needs more attention, and the youngest is " detestable".
Only child: He is the favorite, he can do everything he wants and his parents buy him everything he wants because is the olny person who can spend their money.
Addopted. Im not sure but i think that his/her parents love him/her, because you dont addopt someone that you dont want to see or something like that.