Trait theory is fascinating! I’ve never studied it fully in depth – I should — but what’s fascinating is that it all started with a list of 18,000 “trait describing adjectives” compiled by a couple of psychologists in the 1930s. It was reduced to around 5000 and then I think to 500 or so and forms the basis of a LOT if not all of the modern ideas involving personality traits.
So it makes sense that a database of words set in relationships with one another in concrete ways describing human psychology would make it easier for an AI to figure out sames and opposites, group things together, make predictions, etc.