Which of the following statements about self-awareness is incorrect?

Which of the following statements about self-awareness is incorrect?
 
  a. Self-awareness occurs earlier in children as a function of the amount of social stimulation they receive.
  b. At 15 weeks of age, the home-reared infant in North America is in contact with its mother for about 20 ofthe time.
 c. At 15 weeks of age, infants in the Ju/'hoansi society of South Africa's Kalahari Desert are in close contactwith their mothers about 70 of the time.
 d. American children develop self-awareness earlier than do Ju/'hoansi children.
  e. Self-awareness comes in stages and not all at once.