The traditional focuses of sociology include social stratification, social class, social mobility, religion, secularization, law, sexuality and deviance.
These were called calceus mulleus, and the name may have been shortened to mules by English speakers. Hence the primary difference between mules and clogs in early days was that clogs were likely to be worn by working people, and mules were fancier and favored by the aristocracy.
Donkey, ***, Burro ... all the same animal, may be a different sub-species though... Whoever said a burro is the cross between a horse and a donkey is wrong... A Mule is a cross between a female horse and a male donkey A Hinny is a cross between a female donkey and a male horse.