Children are sociopaths at an early age, yes. But social conditioning has a pretty massive effect by the time they reach their teens. So if said children live in a society where morality and selflessness are emphasized, then it'll be imprinted on them by their teenage years. Thus, ruthlessness and pursuing self-interest over morality are traits that have to be relearned. In effect, you're both right about children being innocent and sociopathic, depending on which stage of development they're in. First they're sociopathic, then more innocent as they conform to their soceity/parents beliefs on morals, and then (possibly) relearning that ruthlessness and self-interest later. Or at least that's how I view it in this case.