Why visual tools improve your thinking: George Lakoff and Mark Johnson

The second argument for using visual tools comes from a book about metaphors. That’s not metaphors as in literary devices but as essential mechanisms to think abstractly.

Lakoff and Johnson argue that how we think is determined by our physical experiences. Orientation —where we are in space— is one of the primary metaphors used to make ideas understandable.

“Human thought processes are largely metaphorical. …Most of our fundamental concepts are organised in terms of one or more spatialisation metaphors.”

So metaphors —especially spatial ones—aim to  provide the physical clarity of concrete experience.
References: Metaphors We Live By (1980) Chicago Press