From the 1920s to the 1950s, behavioral psychology dominated much of psychological thought, but the cognitive revolution of the 1950s revealed cracks in the theories of the radical behaviorists, and cognitive psychology eventually managed to gain the upper hand.
The heavyweight division in mixed martial arts (MMA) generally groups fighters between 205 and 265 lb (93 and 120 kg). Although many ambiguities exist within the lower weight classes regarding division naming and weight limits, the Heavyweight division is, for the most part, uniform.
A featherweight boxer weighs in at a limit of 126 pounds (57 kg). In the early days of the division, this limit fluctuated. The British have generally always recognized the limit at 126 pounds, but in America the weight limit was at first 114 pounds. An early champion, George Dixon, moved the limit to 120 and then 122 pounds.