The Mixed-Up Twins of Bogota

In Colombia, because of a hospital mix-up, two pairs of identical twins were raised as two pairs of fraternal twins. One set was raised by a poor rural family in a remote hamlet, the other by a middle class family in Bogota. Just hearing about this story, you know how those psychologists who study twins itched to get at them. After the shock of learning all this passed, they did agree to be tested, and according to Susan Dominus in the Times, the separated twins did not test as very much alike. So keep this example on hand to set beside all those cute stories about separated twins who ended up liking the same candy or marrying spouses with the same name or whatever. Really big differences in how you grow up can override genetic similarity.