Redheads are more susceptible to pain than blondes and brunettes.
Ten red-haired women between 19 and 40 years of age and ten more with dark hair were given a commonly-used inhaled anaesthetic in the study. After each dose of the anaesthetic, the women were given a standard electric shock.
The process was repeated until the women said they felt no pain. Their reflexes were also monitored to assess the effectiveness of the painkiller. The researchers found that red heads required 20 per cent more aesthetic to dull the pain.
