Sui generis
A similar case that led to the use of the label "sui generis" is the relationship of New Caledonia relative to France, because the legal status of New Caledonia can aptly be said to lie somewhere between a French overseas collectivity and a sovereign nation. Although other examples of such status for other dependent or disputed territories may exist, this arrangement is unique within the French realm.
Behavioural genetics
Selective breeding and the domestication of animals is perhaps the earliest evidence that humans considered the idea that individual differences in behaviour could be due to natural causes. Plato and Aristotle each speculated on the basis and mechanisms of inheritance of behavioural characteristics. Plato, for example, argued in "The Republic" that selective breeding among the citizenry to encourage the development of some traits and discourage others, what today might be called eugenics, was to be encouraged in the pursuit of an ideal society. Behavioural genetic concepts also existed during the English renaissance, where William Shakespeare perhaps first coined the terms "nature" versus "nurture" in "The Tempest", where he wrote in Act IV, Scene I, that Caliban was "A devil, a born devil, on whose nature Nurture can never stick".