It is not necessarily BIOLOGICAL.

It is most likely SOCIAL.

Girls are raised to be AIRHEADS.

Role models for girls include: Barbie, Marilyn Monroe, Madonna, Britney Spears, Paris Hilton, Kim Kardashian, Taylor Swift, etc. Emphasis on looks & beauty for girls.

Parents have to encourage their sons & daughters to enjoy school, learning, education, math, science, proper English, learn French, Mandarin, Spanish, German.

Parents have to raise their sons & daughters to be warriors instead of WIMPS.

Never forget that girls / women have graduated from difficult college / university programs which require math and science. 

There are tv shows about doctors, hospitals, lawyers, police FBI, CSI so teenagers are more aware of medical & law professions.

People have less media exposure to scientists, engineers & computer programmers.
But since kids, teenagers are addicted to iPads, smartphones, internet, Instagram, maybe they will be now interested in computer science / computer engineering.