Thanks, Siebe, for quoting that sutta. I had forgotten the name of the sutta. I just revised the post to cite it.
You asked: “Do i understand it correctly, Lal, that those anusaya can only be triggered after a certain period when the brain is ripened to a certain degree?”
Yes. As I explained in the previous post, these anusaya start getting triggered gradually as the baby grows. By age 7, that process is complete.
There are some other subtle points involved here too. For example, being able to taste the sweetness of sugar is not the same as having craving for it. An Arahant tastes the sweetness of sugar, but does not form any attachments; see, “Kāma Guna, Kāma, Kāma Rāga, Kāmaccanda“.