>This is because your lot is pursuing careers, reproducing later, and having fewer kids for lifestyle reasons.

I see. Interesting.

There is a little evidence here and I can imagine several conclusions can be derived from it. Your argument is fairly strong, but I wouldn't say sound. For example, lets say everyone breeds to the maxium capacity, how fast will the world run out of room? 200 years or so, right? In any case, knowing that, I could produce an equally strong conclusion suggesting that those of us waiting longer to have kids, and having less kids is not personal selfishness, it is a selfish gene trying to gauarantee sufficient resources for future replications of the gene. So a selfish gene disguiesed as an altrusitic gene makes the individual look selfish at the same time.

But the more repsectable possibility: by delaying reproduction we are hoping that the stability of the foundation created in middle age will benefit offspring more than those who don't wait. If this sounds ridiculous to you, I'd like to know your opinion on why we as organisms remain children much longer than other species. Based on what you're saying (and more impoartanly, what you're overlooking) it would be more beneficial to be sexually mature at the age of 0, not 14.