Mass Effect, when you are talking to the Rachni Queen. She is explaining why her children are attacking people. The children have been kept separate from their mother, and therefore she has not been able to "sing" to them (meaning she has not been able to teach them lessons about life and such). She then says (possibly not the exact quote) "we havent been allowed to sing to our children. If we don't sing to our children, they will only know fear". As a parent, this definitely struck a chord with me (especially the part about being kept separate from your children). If you don't talk to your kids and teach them morals, maybe they will strike out at those around them...
Who would've thought that emotion could be stirred up from a chat with a giant space spider!