Theories of Language Learning (Hybrid Theory)

I'm a fan of the hybrid theory for language learning in children. I believe the third theory that states that human language is innate (pg 174 "The Developing Person through the Lifespan"), but I also believe children won't be able to use language in it's full ability unless someone teaches them as it is stated in the first language learning theory(pg 172). The reason why humans use language though is due to the fact that we are social creatures (pg 173). I believe the process of learning language has to do with all three of these theories tied together which is why our language is so complex. I don't believe babies would get past the babbling stage unless they had a parent sit down with them and communicate with them. I remember being taught in high school a case study about a girl named Genie who was locked in her basement for years and was only communicated with to be fed or use the bathroom. Genie babbled much like a baby but did not know how to respond appropriately to conversation or know many actual words. This is why even though language is innate, it has to be taught properly in order for a person to grow up knowing words, syllables, and correct grammar.