> Taking care of an ailing parent is in no way connected to maximizing one's returns on anything (except maybe fulfilling a sense of what you "ought" to do).
Unless that act teaches your own children how to treat you later in life.
I know it is a semantics argument, but there's a difference between "X ends up acting in alignment with self interest" and "X's actions are motivated/guided by self interest".
Motives aren't really relevant here. Reciprocation or replication by others does happen, regardless of motive, so caring for family and friends (or strangers for that matter) is very much in one's self interest. I took issue only with the idea that it's not.
Unless that act teaches your own children how to treat you later in life.