The current Western practice of __________ delays gross-motor milestones of rolling, sitting, and crawling.
A) exposing infants to tummy time
B) using rear-facing carseats
C) putting babies in exersaucers
D) having babies sleep on their backs
Question 2
Among the __________, babies hold their heads up, sit alone, and walk considerably earlier than North American infants.
A) Gusii of Kenya
B) West Indians of Jamaica
C) rural northeastern Chinese
D) Zinacanteco Indians of southern Mexico