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It's not true for identical twins, but it is true for fraternal twins.
Unlike identical twins, who both come from the same fertilized egg, fraternal twins develop from two different eggs released at the same time. (Although they have the same birthday, fraternal twins are genetically no more alike than any other sibling.) The tendency to release more than one egg in a single cycle (hyperovulation) is a genetic trait that can be passed from mother to child.
Hyperovulation also happens for other reasons that have nothing to do with genetics. Women in their early 30s, for example, are significantly more likely than women under 20 to release more than one egg at a time. (This tendency starts to decrease after the age of 35, however.)
Contrary to widespread belief, twinning doesn't skip a generation, although it may sometimes appear to when a son inherits the gene and passes it on to his daughter. A man who carries the gene doesn't have a greater chance of having twins himself because his genes don't affect his partner's ovulation.
By contrast, identical twins don't run in families. The splitting of a fertilized egg seems to happen at random. A woman who is an identical twin is no more likely to give birth to twins than anyone else.
Follow one woman through her pregnancy with twins and watch her give birth.