The 4 major brain hormones (neurotransmitters) that determine our core personalities are:
Every single one of us has a distinct personality because the balance between the 4 major brain hormones is unique to every individual - just like our faces or fingerprints. Our core personality is always just below the surface, silently driving our actions.
The balance of our 4 major brain hormones occurs at birth. That balance is structured by the impact of the earths seasonal energy fields on our bodies when we independently interact with them for the very first time.