Only 1 in 10,000 neurotypical people in the West have AP — the ability to effortlessly, without context, name the note sounded by a violin or a vacuum cleaner (“That's an F-sharp!”). Among those on the autism spectrum, the number rises to 8%, roughly 1 in 13. For people born blind or who lost their sight early in infancy, it is 45%. AP, Ockelford argues, enables children to sound out and tinker with familiar tunes; that experimentation leads to a deep grasp of musical structure.
Those are quite extraordinary differences.
Perhaps unsurprisingly, children whose first language is tonal (Vietnamese or Mandarin) in this study, and who start studying music at an early age, are much more likely to develop perfect pitch. So absolute pitch is an acquired skill, but one which requires training at a very early age. Four is problematic and eight seems to be definitely too old.