Dr. C. George Boeree

Puberty is the beginning of adolescence.  But when is puberty, exactly?  The hormonal changes begin as early as 8 years old.  But the physical changes don't usually make themselves known for several years later.

In modern western societies, we usually say that puberty starts between 11 and 12 years old for girls, and between 12 and 13 for boys.  95% of all girls will start somewhere between 8 1/2 and 13, and 95% of boys a year or more later, between 9 1/2 and 15.

The first clear sign of puberty for girls is the beginnings of breast development, around the age of 12. There is also an overall growth spurt that begins around 10 1/2, peaks at 12, and begins to slow around 14.  But the main mark of puberty is menarche (pronounced MEN-ark-ee), the first period.   In modern western societies, it tends to happen between 12 and 13.

Curiously, in 1890, a girl's first period tended to occur at 14 or 15.  In 1840, it often began as late as 17!  It is thought that these variations were primarily due to differences in nutrition.  Also notice that the average age at which a woman marries today is around 25.  In 1890, it was around 22.  In the Middle Ages, it could be as young as 12 or 14.  (Remember that Romeo and Juliet were only 16!)

The first mark of puberty in boys is the start of testes growth around the age of 13, and penis growth around 14.  The growth spurt for boys tends to begin at 12 1/2, peak at 14, and slows by 16 - hence the common sight of girls towering over their partners at school dances!

The growth spurt we mentioned is about 8 to 10 cm (3 to  4 inches) of height a year for both girls and boys - similar to the rate of growth back when they were only 2 years old!  With this spurt, there is a significant loss of fat in boys, especially in the limbs, which accounts for the common "beanpole" look among adolescents.  Girls may also lose fat, but not as dramatically as boys.  An unfortunate tendency today, however, is the onset of obesity in adolescence due to the high fat, high sugar diet many teens adopt.

Adolescence is definitely a time of increasing strength:  A 14 year old boy has 14 times the muscle cells of a 5 year old boy.  A 14 year old girl has 10 times the muscle cells of a 5 year old girl.

Psychologically, adolescence is a pretty busy time.  Becoming a sexual adult involves a number of things that may very well have instinctual roots:  Boys compete with each other for attention by shows of physical ability and acts of daring, often bordering on the insane; girls compete for the attention of boys, most commonly by attempting to enhance their appearance.  Different cultures have different details, but the pattern is pretty universal.

Ruffino, Sean, and Carol Ann

The single most important thing seems to be social acceptance.  If you do not have a circle of friends, in the teenage world you are nothing.  For many teenagers, whether their isolation is due to a family move or social inhibition, physical abnormalities or not meeting local standards of attractiveness, not being accepted is a cause of depression and sometimes suicide.  I believe this response is very likely one we have inherited from our very social pre-human ancestors:  No group, and you might as well be dead.

In later adolescence, two things dominate a teenager's mind:  Finding a boyfriend or girlfriend and finding a way to make a living.  The way these needs are expressed can range from trying to have sex with whomever will have you and making, borrowing, or stealing enough money to make a good showing, to a serious effort at creating the foundation for a lifelong partnership based on love and training for a financially and personally rewarding career.

The end of adolescence is as much a social thing as a physiological thing, so it is very hard to say when that is, but in western cultures, we usually think of 18 as a convenient mark.  But, with work and family delayed as long as they are nowadays, a lot of the traditional tasks of adolescents continue well into the 20's.

Because the adolescent is in the process of breaking away from his or her parents, there is often conflict between them.  Ideally, adolescents acknowledge their parents wisdom and politely leave the house, while parent trust their children to make their own decisions and let them go.  Unfortunately, it often doesn't work that way.  It is almost as if nature is making us so repugnant to each other that we are absolutely eager to go our separate ways.

These conflicts between parents and their adolescent children go back many generations.  Socrates and other Greek philosophers complained about this upcoming generation of spoiled slackers, as did writers in the renaissance and all the centuries.  Here's a paraphrase of one such complaint:

"Where did you go?"
"I did not go anywhere."
"If you did not go anywhere, why do you idle about?  Go to school...  Do not wander about in the street....  Don't stand about in the public square or wander about the boulevard....  You who wander about in the public square, would you achieve success?...  Because my heart had been sated with weariness of you, I kept away from you and heeded not your fears and grumblings....  Because of your clamorings... I was angry with you....  Because you do not look to your humanity, my heart was carried off as if by an evil wind.  Your grumblings have put an end to me, you have brought me to the point of death."
This is a piece of a conversation between a Sumerian youth and his father, recorded in cuneiform some 3 or 4 thousand years ago.  (From S. N. Kramer, The Sumerians, University of Chicago Press, 1963.)  Funny, I could have sworn I heard this conversation just the other day!

© Copyright 2003, 2005, 2009, C. George Boeree