The mystery of twins studies of identical twins who were separated at birth have revealed the most significant data in the research field of behavioral genetics. oneOne of the most revealing pair of twins is known as the jimJim twins. jim springerJim Springer and jim lewisJim Lewis who were separated at birth and reunited 39 years'years later have many characteristics in common; each brother was told that his brother had died at birth. inIn other words, they were unaware of each other: both brothers look alike in terms of physical appearance, for example they share the same facial features so one cannot tell them apart. likewiseLikewise their voices sound exactly the same: one could easily mistake one for another: springerSpringer and lewisLewis are alike in that they are friendly, kind and generous; therefore, they are both popular with friends. anotherAnother similarity is that , neither springerSpringer nor lewisLewis has a temper: even if they get angry they don't show it , in springer. Springer smokes salemSalem cigarettes and so does lewis like springer lewisLewis. Like Springer, Lewis was married twice. springersSpringer's first wife was named lindaLinda and so was lewis inLewis's. In the same way, their second wives were named betty finally springerBetty. Finally, Springer named his son james allen lewisJames Allen, and Lewis named his son james allen althoughJames Allen. Although the jimJim brothers were not reunited until 39 years later, they had led strikingly similar lives: this shows that whether they grow up together or not identical twins not only look alike but also behave in quite similar ways.