Nine- to thirteen-year-olds are going through an intense period of physical, social, and emotional development--an upheaval greater than any period since their first two years of life. Against this backdrop, your responsibility as a parent is to help prepare your child for puberty.

Your child's body is changing. Some girls begin pubertal changes as early as age eight and some boys begin as early as age nine, so it is important to start talking about these changes by the third or fourth grade. The average age for puberty to begin for girls is between 8 and 10; boys generally begin this process a bit later, between ages 10 and 12. The entire process--from the first noticeable physical signs, like breast budding and underarm hair, to a fully adult body--usually takes four or five years.

Girls need to be prepared for their first period. The average age of first menstruation is now 12.5 years. That means half of all girls will have their first period before the seventh grade, and many will begin as early as the fourth grade. A girl's first period is likely to come about two years after her breasts first begin to develop. Think through in advance how you want handle your daughter's first period; consider a special gift or celebration of some kind.

Boys also need to be prepared for the changes their bodies will go through. Be sure to let your son know about the possibility that he will have a nocturnal emission (wet dream). Let him know that you will understand if you find stained sheets or ask him to strip the bed and put the sheets in the laundry basket. Boys need to know about the changes they should expect in penis and testicle size, but it's also important to allay their worries about this: explain that most adult penises are between two and four inches flaccid and five to seven inches when erect, and that for most adults, penis size does not affect sexual satisfaction.

These dramatic physical changes leave many pre-teens wondering, "Am I normal?" They compare their development to their friends'; they worry about their breast or penis size and their fluctuating feelings. They may become preoccupied with their appearance.

Beset by these feelings, your pre-teens need to know that everyone's body changes at its own rate and that puberty begins and ends at different ages for different people. Reassure them that they are normal. You might want to give them some books that are specially written to help answer pre-teens' questions about puberty. You might also want to look for a school, church, or community program on puberty for parents and children together.

Here are some other changes that you can expect:

-- During these years, friends become more important. School cliques may influence your child's choice of friends, clothes, and spare time activities. Your pre-teen will probably experience peer pressure to try smoking and drinking.

-- Parents become less important. Expect your child to fight with you more, to not want to be seen with you in public places, and to be critical of how you dress and behave. No one is as critical of adults as a pre-teenager. They are beginning to separate from you. This is a good thing--you do not want them living with you when they are thirty!

-- Pre-teens are likely to experience their first adult-like erotic feelings. Many begin to masturbate for sexual pleasure; many develop their first crushes and attractions; some will begin to experiment with sexual behaviors.

Nothing substitutes for open, honest discussions with you. Share with your pre-teen your own stories about your puberty. How did it feel to have your first wet dream or your first period? How did you feel about your body? Did you have struggles with parents and friends? What do you remember thinking and feeling about sex?

Look for teachable moments that give you the opportunity to talk with your child about sexuality issues. Most important, be sure your child knows that you are always there to listen and answer his or her questions--and that you love them.

-- Debra Haffner

For more information on this topic, check out "First Love: The Pre-Teen Years," an excerpt from Haffner's book From Diapers to Dating, at the Internet address below: