So to avoid any surprises when you give birth, couples are now being offered DNA tests to check if they are going to pass on red hair to their off-spring.
The simple test, from the Who Do You Think You Are? Live exhibition at Olympia in London in February, will be able to tell you just that.
Dr Jim Wilson, chief scientist at the company behind the test, said: "Through a simple saliva test to determine deep ancestry, we can also identify whether an individual is a carrier of any of the three common red-head variants in the gene MCIR.
"This means that families can carry a variant for generations, and when one carrier has children with another carrier, a red-headed baby can appear seemingly out of nowehere."
Recent studies have hinted that millions of Brits are carriers of the red-headed gene, which means that although they may have a different colour hair, they may be exposed to an increased number of health risks like skin cancer, Parkinson's disease and sensitivity to pain.
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