Early discourse about UD borrowed heavily from the discourse of usability. Yet Universal Design is usability with a key difference: it has always been more closely wed to the goal of making the world more accessible for people with disabilities. While usability principles sometimes listed people with disabilities as one key constituency, UD has placed individuals with disabilities at the center. One of the philosophical bases of universal design is that disability is partially socially constructed. Genes alone don’t disable people; an environment designed only for people with a certain body disables people whose bodies don’t conform to this narrow norm. Changing this environment is a means of intervening in the social construction of disability—­interaction between person and world is not only made more efficient, it is made less oppressive.

— Academic Ableism by Jay T Dolmage