Neuroscience has located a section of the female brain that is seemingly geared towards wanting to wear make-up.
Located in the primitive hind brain, the so dubbed 'Number 7' section is not present in male brains.
"We've studied this group of neurons quite extensively," said Max Factor, who led the study. "It fires exclusively when women think about applying make-up, or buying make-up."
From extensive studies with women who don't wear make-up and transgendered people, the Number 7 section of the brain seems to co-ordinate colour functions and fine motor control.
"The transgendered study we conducted was very revealing," said Factor. "It showed us that people who claim to have been born female have this section in their brains. The application of female hormones during their transition ramps up the activity in this area until it is as fully functioning as a genetic woman's Number 7 section."
Not all women have the Number 7 section, and those that don't generally do not apply make-up, or apply it because of perceived social pressure. Interestingly, some men appear to have the Number 7 section in their brain, but yet show no desire to become trasngendered, or wear make-up.
"We're yet to find out how these men are using this section," admitted Factor.
Given the location in the brain, it is believed that the Number 7 section has evolved from a more primitive use.
"We believe," said Factor, "that this area evolved from the need to appear attractive and mate receptive. Other animals, from monitor lizards to Rhesus macaques have the Number 7 section, and when it's removed, they cease to show secondary sexual characteristics that indicate fertility."
According to Factor, as humans give off a false fertility reading, this area of the brain is overdeveloped, and helps women appear more attractive than they otherwise would.
"We have been tossing around a few ideas for a proper name for the section," said Factor. "Our best one so far is the shagme, which is Latin for 'I am fertile'."