You're right - 1.618 IS a very specific number - that is why it ISN'T found in the proportions of most human bodies.
Is phi a mystical number as claimed in The Da Vinci Code? - The Straight Dope
quote:
Your height divided by the distance from your belly button to the floor = phi. Get out. Behold the line segment in the drawing. The only people of height AC with their belly buttons at point B are named Igor. On me the ratio is about 1.7, not 1.618+.