No two children, however, grow at precisely the same speed. Just as all human beings differ in appearance and behavior, so they differ in the way they grow. One may still look like a child, with his straight slim build and small-boy features. Another may be in the gawky stage. Yet another may look like a grown man, even though he is just starting high school.
Growth also produces great differences in build.
While one young girl is short and slender, another may be short and plump. Again, some boys and girls are tall and slender, others tall and heavy. Similar differences in shape and size can be seen in any group of adults. At about twenty years of age, the average boy is five inches taller and fifteen pounds heavier than the average girl. At eighteen, girls are fully grown, while boys continue growing a little taller up to the age of twenty or so.