Yes. It is true that “distorted saññā” is “built-in” to our mental AND physical bodies by kammic energy (via Paṭicca Samuppāda.)
However, that “distorted saññā” in the mental body (specifically the “seat of the mind” or hadaya vatthu) cannot be triggered until the hadaya vatthu receives a sensory input.
As we have discussed in that post you quoted, that sensory signal must be first processed by the brain. Depending on the status of brain development, some signals do not get processed or sent to the hadaya vatthu. That is the main point I tried to convey in that post. Also see “Brain – Interface between Mind and Body.”
Only after seven years of age (when the brain is fully developed), the hadaya vatthu receives most sensory signals.