Colour vision - Jameson and Huvich 1968; S.S. Stevens (1956, Harvard) Steven's power law
This type of scientific method and progressive refinement of laws was considered respectable, even to most behaviourists. Several of the early researchers in cognitive psychology, like, George Miller, Ulric Neisser and Donald A. Norman, received their Ph.D. training is psychoaccoustics. (Piaget's work had to wait for independent confirmation of his results using standardised procedures.)