The History of Twins and their Character

“The exceedingly close resemblance attributed to twins has been the subject of many novels and inlays, and most persons have felt a desire to know upon what basis of truth those works of fiction may rest. But twins have many other claims to attention, one of which will be discussed in the present memoir. It is, that their history affords means of distinguishing between the effects of tendencies received at birth and of those that were imposed by the circumstances of their after-lives; in other words, between the effects of nature and of nurture...”