According to conventional wisdom, twins not only run in families, but they also — for some strange reason — always skip at least one generation. ... Because there is no known gene that influences this process, it is considered a mere coincidence when one extended family has multiple sets of identical twins.

Which parent carries the gene for twins?

For a given pregnancy, the odds of conceiving fraternal twins are only determined by the mother's genetics, not the father's. Fraternal twins happen when two eggs are simultaneously fertilised instead of just one.

How does twins run in the family?

Non-identical (fraternal) twins tend to run in families. But identical twins don't. Non-identical twins are the result of two separate eggs being fertilised by two separate sperm. ... If he has daughters, they may inherit the gene, and one day go on to have fraternal twins.