If two parents have any redhead genes, they can have a redhead child even if they both have dark hair.
The main gene that underlies red hair is Melanocortin 1 Receptor, or MC1R.
This protein that it encodes is a receptor that plays a role in pigment synthesis.
The Melanocortin 1 Receptor gene has several alleles, one of which is related to red hair.
Red hair is a recessive trait.
If one of the parents passed on a version of the gene associated with dark hair, the individual will have dark hair and will be a carrier of the redhead gene, which he could pass on to his children.
Eight different genes, are associated with red hair.
Only two percent of the global population have red hair.
In some areas, such as Scotland and Ireland, red hair is more common, estimated that about ten percent of the population.
Redheads having features such as being rebellious, defying authority and conventions and possibly 6quick to get angry, have not been confirmed on scientific studies.
Some physical traits are characteristic of redheads:
lower pain tolerance and require larger doses of painkillers, and anesthetic
Redheads also get colder faster.
Since red hair is a recessive trait, the children of two redheaded parents will almost always be redheaded as well.
If only one parent is redheaded and the other has brown hair, there is a higher chance that the children will display the dominant trait and will have brown hair.
The children of those couples, in which one partner is redheaded and the other is not, will most likely not have red hair, but they will be carriers of the redhead gene.