You have probably heard about mesomorph, ectomorph and endomorph, in the context of fitness. Those terms are originally from psychology and were created by psychologist William Herbert Sheldon. His theory was that body type and personality are linked. He said that skinny guys are resistant to hypnosis. Does this explain why all chads are such fucking drones?
https://en.wikipedia.org/wiki/William_Herbert_Sheldon
https://www.innerexplorations.com/catpsy/t1c4.htm