Plenty is doing.
"Enough has been said [here] to prove that an extremely close personal resemblance frequently exists between twins of the same sex. and that, although the resemblance usually diminishes as they grow into manhood and womanhood, some cases occur in which the resemblance is lessened in a hardly perceptible degree."
Disclaimer: this quote appears here only to spark discussion. It is not endorsed one way or the other. Make up your own mind. Or just refresh the page for another viewpoint. From a collection assembled by the late Chris Brand.