During their growth spurt, some boys become tall and reedy, and they may develop an interest in muscle-building (looking like a “weakling” makes them vulnerable to teasing). However, boys should wait until late puberty before they begin any type of weight-lifting program. In addition to wanting to grow taller and more muscular, your son will be interested in the development of his reproductive organs. Growth of pubic hair is the most obvious indication of male puberty, but penile growth and enlargement of the testes actually begins before that. (Some boys start changing as early as age 10, and almost all boys will see some signs of development by the time they’re 13 and a half.) Teenage boys will also notice that although they’ve had penile erections for their entire lives, these erections will become much more frequent during early or mid-puberty because of an increase in male sex hormones. All boys begin to experience erections when they don’t anticipate them. (Sometimes these erections occur at the most awkward moments, like while standing in the hall talking to a girl or when called upon in class.) They also occur frequently during sleep and some times result in nocturnal emissions. These are described as “wet dreams” because semen is released during sleep. This ejaculation is perfectly normal and is a sign that a boy is maturing sexually. With age, wet dreams will become less frequent because of masturbation and intercourse. Boys sometimes are concerned about the development of the testes and penis. In most males, one testicle (usually the left) hangs lower than the other. Penis size also brings up feelings of anxiety, because boys with small penises are often teased by their peers. Most boys don’t realize that the size of another boy’s flaccid penis may be a poor indication of how large it is when erect. Also, male sexual function has nothing to do with penis size. Give your son the facts and tell him there’s no reason for concern. As a boy’s larynx grows, it causes his voice to “crack”—a source of embarrassment for many boys. Once his larynx has enlarged to its full growth, your son’s voice will deepen. Gone will be the days when he’s be mistaken for his mother or sister when he answers the telephone!