Courtesy of The Motley Fool:

An Englishman, a Scotsman, and a Nigerian are sitting in the maternity ward of a hospital waiting for the births of their respective children.

They are all very nervous, pacing, fidgeting, and fretting. Suddenly a nurse bursts through the double doors saying, “Gentlemen you won’t believe this, but your wives have all had their babies within five minutes of each other—and they’re all healthy boys!”

The fathers are ecstatic and congratulate each other over and over.

“We do have one slight problem,” admits the nurse, “In all the confusion we might have mixed the babies up as we rushed them to the nursery. We’d be grateful if you could join us there so we can identify them.”

The Scotsman races past the nurse. Once inside the nursery he picks up a dark-skinned infant saying, “There’s no doubt about it, this boy is mine!”

The nurse looks bewildered, “Well sir of all the babies I would have thought that this child would be most likely to be of Nigerian descent.”

“True,” says the Scotsman, “but one of the other two is English and I’m not taking any chances.”