If there is a psychological urge that drives us to build, it must stem from a confrontation with emptiness. By build we may include physical structures (perhaps architecture), digital content, mental constructs, and interpersonal relationships. By emptiness we may include vacancy in physical space (perhaps the post-industrial landscape), a lack of stimuli, an absent mind, loneliness.
The practice of architecture, then, is an act of catharsis.
Buildings fill up the void, provide a framework for interaction, create a stimulus for activity and activation, mark a reference point in space and time for future memories, past actions.