From Opeyemi Salawu:

Re: Built-in brain “templates” may clue tots to threats (Sept. 18): I quite agree with your findings and it is not a new thing that babies are afraid of these creatures (spiders or snakes) even without seeing one. Well, when it comes to heredity, I would say ‘the history of mankind is written in the genes’. I also want you to consider the fact that infants would cry at the sound of a roar. This is not because they have never seen a lion but because their brain signals ‘DANGER’. Why? It’s written in the genetic configuration. Why is it written specifically in the genes? A non-scientist (a religious man) would tell you that it is ‘reincarnation’-the believe that we were once in existence and when the body dies, it gets reborn in a new life’. In his previous life, he had encounters and nobody dares to forget his deepest fear. It is only natural that a new born cannot speak instantly. Language is not a test.

Well, in the more rational sense, it is not a surprise that human brain is not blank, I mean it has never been blank. It contains hidden information and has infants grow up, they either add to it or develop what’s already there. You might what to consider ‘Environmental factors as the main focus point.