My take is the human brain learns concepts primarily through differentiation. To a newly born child who has no concept of door or a wall, has no reason to see the two as being different parts. Different languages form different differentiations, but one can always compound concepts, and differentiate them differently.
To extend: there will also be general alignment tendencies towards those readily mapped and expressed concepts within available language. Hard but useful concepts can get mapped to idioms. Modes of categorization will be influenced by these factors, which in turn influences many processes.
