If I understood correctly, babies cannot focus their eyes properly for the first two months, and this may indicate they are learning some universal 3D-spatial models into their heads, as a prerequisite for many of the other instincts they have as later developmental windows. So there has to be some thread of signals that string this system to the later affects/instincts, such as the fear of heights. It is also funny to relate the ability of many ungulate babies ability to walk immediately on birth, meaning there has to be some seriously robust set of instincts that coordinate this for them. This blurs the … requirements… between instinctual and learned coordination, but I believe in the end all cortex-having brains would benefit from moving away from instincts and into learned models.
Related: Gene for upright walk in humans discovered: https://www.theguardian.com/science/2008/jun/02/genetics.medicalresearch