I have noticed that in many cultures, it is expected that family members love and care about each other.

 

This has made me wonder why we are expected to love these people in our lives. Are we expected to love family members simply because we have similar genetics?

 

Or, is this love created through being forced to live together under the same roof? Could another possible explanation could be that we are ethically driven to love the people that care for us, such as our parents?

You might want to check out the wiki page on oxytocin and vasopressin. Lots of good information about the process there.

You might want to check out the wiki page on oxytocin and vasopressin. Lots of good information about the process there.

 

I think they might be more interested in the biological function of altruism, not the chemical aspect. You could check the wiki page on altruism in the animal kingdom, I'm sure there will be some history on it.

Check out the wiki page on kin selection as well. It is in your interest as an organism to pass on your genes, and you can do that by helping others who share the same genes as you - aka, relatives.

 

http://en.wikipedia.org/wiki/Kin_selection