DR. WALLACE: I'm a very shy person, and because of this, I miss out on a lot of excitement and fun. What really bothers me is that almost everyone I know is outgoing and doesn't appear to be in the least bit shy.

My older sister (she's outgoing) said that she was also shy when she was young and that everyone is shy at one time or another. Is this true? I sure hope so. — Maria, Odessa, Tex.

MARIA: According to a survey by Dr. Philip Zimbardo and a research team at Stanford University that has done extensive studies, shyness is almost a normal human emotion that is universal in scope.

Only 7 percent of the people they questioned claimed that they had never been shy. That leaves a whopping 93 percent who can't make that claim. Shyness is equally common among males and females with teens experiencing the greatest shyness. But Dr. Zimbardo discovered that during the teen years, girls were shyer than boys mainly because of the physical changes that occur.

Dr. Mary Lou Vandenburg, author of "Coping with Being Shy," states that the first step in overcoming shyness or making any personal changes in your life should start with self-acceptance. Optimistic thoughts can change your life.

WE ARE CAUTIOUS WHEN HAVING SEX

DR. WALLACE: No lectures please. Just a simple answer will be sufficient. I'm 16 and so is my boyfriend. This past summer, we entered into a sexual relationship. We are cautious. He uses a condom every time we are intimate. Still, I'm aware that using a condom is not 100 percent effective. I really want to know the percent that condoms are effective.

There is no way that I want to become pregnant. I repeat, no way do I want to become pregnant. Please don't tell me that the only safe way to avoid pregnancy is to avoid sex. That is quite obvious. — Nameless, Chicago, Ill.

NAMELESS: The most effective condoms are the latex condoms, not natural membrane condoms.

For those who choose to be sexually active, it is imperative that a latex condom is used. According to the Centers for Disease Control and Prevention, laboratory studies show that latex condoms provide a continuous barrier to microorganisms including HIV as well as sperm. Natural membrane condoms cannot make this same claim. Latex condoms are highly effective (98 percent) when used consistently and correctly during sexual encounters.

GIRLS SMOKE MORE THAN BOYS

DR. WALLACE: Is it true that more girls now smoke than boys? I find this hard to believe. I got this info from my health teacher. — Lisa, Chicago, Ill.

LISA: Teenage girls are, indeed, caught up in a smoking spiral and smoking in this group is rising sharply. Not so long ago, more teenage boys smoked than girls. Not so today. The American Cancer Society reports that about 25 percent of girls between the ages of 12 and 19 now smoke cigarettes. And this is more than the number of boys the same age who smoke. Tobacco companies spend millions of dollars directing advertising to convince females that smoking is fashionable.

Dr. Robert Wallace welcomes questions from readers. Although he is unable to reply to all of them individually, he will answer as many as possible in this column. E-mail him at rwallace@galesburg.net. To find out more about Dr. Robert Wallace and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.