I think the thread has gotten way off topic. The article is about kindness, not altruism. Kindness is, in my experience, doing something that makes someone else feel good, regardless of how it makes you feel. You do something, in kind, as it reciprocates the emotive intent to be helpful. You don't do something, in kind, as it creates a lack (for either party) as a result of that act. Self sacrifice and kindness are completely unrelated. Self sacrifice should not, and must not, be a deciding factor in what determines kindness as it confuses the moral agent motivating the act.