Here is a definition from Wikipedia (emphasis mine):
"Instinct is the inherent inclination of a living organism toward a particular behavior. The fixed action patterns are unlearned and inherited.
Instinctual actions - in contrast to actions based on learning - have no learning curve, they are hard-wired and ready to use without learning. Some instinctual behaviors depend on maturational processes to appear."
Viljo's processes are maturing. : )