noun, Psychiatry. 1. an inability to speak, due to a physical defect, conscious refusal, or psychogenic inhibition. Origin of mutism.
1 A new study finds girls are developing breasts earlier than ever before; American boys and girls are entering puberty about five years younger than they did in 1920.
Girls may enter puberty at seven, but will experience a majority of their growth in height when they are around 10.5 years old. Boys may begin puberty at the age of eight, but experience growth when they are around 13 years old. Since girls enter puberty before boys, they also experience growth spurts early. This can result in girls towering over boys of the same age. On an average, boys grow the fastest between the ages of 14 and 15.