[Declanomous]

On an evolutionary scale that's true, but on an interpersonal level it's less true. It's not like a person is more valuable because they are an only child.

[harryh]

As child mortality decreases people tend to have fewer children. This data point contradicts your assertion.

It makes people uncomfortable to think about people in economic terms(1) but that doesn't mean those uncomfortable people are right.

1. We see this in many areas of society from health care funding to liability laws.