I don’t have kids, and don’t plan on having kids (for a variety of reasons that aren’t relevant here). I do have a niece in whom I’ll see 1/4 of my genetic material passed along. So, much like cooperative breeders, I’ll invest in my niece as much as I can, thank you.
That said, many friends and colleagues have children, and it always amazed me how well they seemingly balanced things. There’s a very eye-opening post over at Small Pond Science on the issue of parenting, academia, and getting one’s priorities straight. I can’t say I disagree.