I'm pretty sure the reason why kids are often spaced two years apart is because they get so darned cute right around a year. It's this golden window, between about nine to eighteen months, where they are nothing but adorable, tottering and crawling around, all grins and babbles and chub. Old enough to be sleeping through the night (mostly), self-feed, and self-play; too young to say "no" or throw tantrums. You get lulled into thinking, why not another?
