Why Do Hybrid Breeds Lay More?

[eggsamillion]

I hope this isn't a really dumb question, but as I am learning more about chickens and chicken breeds, I've been wondering why hybrids lay better than the (often heritage) breeds from which they're produced. For example, if you cross a Rhode Island Red rooster with a Barred Rock hen, you get a Black Sex Link hybrid, said to lay eggs at a rate superior than either parent breed. Same with other hybrids like Golden Comets, Amberlinks, etc.. But why would the offspring of these two breeds be a better layer than the original breeds? Can anyone explain this to me? Thanks!

 

[azelgin]

Hybrid Vigor - lots of info on the internet explaining it