Home Biological aspects of sexuality Anatomy & development At puberty boys develop a reliable arousal cycle

At puberty boys develop a reliable arousal cycle

From a young age, many boys already demonstrate a more active and outgoing personality than most girls. Boys enjoy physical activities such as sport where conversation is minimal. This gender difference is apparent before the onset of adolescence and is not attributable solely to hormones. The changes at puberty are not limited to physical changes. There are emotional and social impacts. There is likely to be competition between boys for opportunities for physical intimacy with girls, uncertainties about approaching the opposite sex and possible concerns about homosexual feelings. Both sexes have a desire to be accepted as part of the social group.

The male sex organ is easily identifiable because boys hold it when they urinate. The proper name for a boy’s willy is penis. There are many slang words for the penis including cock, dick and prick. The penis and testicles increase in size at adolescence and boys become sexually active. During puberty, hormones cause boys to experience sexual arousal. They feel excited when they think about a person they are sexually attracted to. Men have an arousal cycle that starts with erection and ends with ejaculation.

Boys can have erections as early as 8 or 9 years old. Instead of being flaccid (or limp), the penis becomes very firm (stiff or hard) and juts out from the body at an angle. Slang words for an erection include a stiffy, hard-on or boner. The average position for men of all ages is just above the horizontal. 15-20% of men carry the penis at 45⁰ above the horizontal while 8-10% have an erection tight against the body. A young boy can hold an erection for longer and at an angle tighter to the body on average than an older man.

Alfred Kinsey’s research indicated that half of all boys have had an orgasm by the age of 7 and two-thirds of them by 12 years old. Until they start ejaculating, these early orgasms tend to be one-offs or sporadic. Fear, apprehension, shock or surprise can produce nervous system responses that have characteristics in common with arousal. A few boys orgasm in response to such stimuli. Less than 1 per cent of boys (0.81%) experience an orgasm (not accompanied by ejaculation) as a one-off in pre-adolescence.

Testosterone is produced by the testes and the ovaries. Testosterone is involved in the development of the male reproductive organs before birth, and the development of secondary sex characteristics at puberty. Prior to puberty, boys and girls have the same levels of testosterone. A boy’s testosterone levels rise significantly (30 times more than before) in puberty, which causes physical changes in the body and also emotional mood swings. Men have considerably more testosterone (exceeding 15-fold) than women at any age. Boys are more susceptible to acne than girls because testosterone causes spots, whereas oestrogen prevents them. When levels of testosterone are high enough, the testes start producing sperm, the penis and testes increase in size, the voice deepens, the chest and shoulders broaden and facial hair starts to grow. Testosterone is a factor in a man’s sex drive.

The first sign of male puberty is usually accelerated growth of the testes and scrotum with reddening and wrinkling of the scrotal skin. Pubic hair growth begins around the same time. The stimulus that triggers accelerated penis growth, also causes the seminal glands and the prostate to enlarge and develop. These glands and the prostate are situated close to the testicles (testes) and contribute 60% and 40% respectively of the seminal fluid.

Most boys (90%) ejaculate for the first time between the ages of 11 and 15. The start of male adolescence is defined by the age at which a boy has his first ejaculation. First ejaculation occurs about a year after the beginning of the accelerated penis growth. Semen is a creamy liquid that contains sperm (the genetic material needed to make a baby), which are produced by the testicles. Semen passes via the urethra (the central tube of the penis) to the outside. Ejaculation (of semen) and male orgasm are two separate phenomena. It is possible for a young boy to orgasm without ejaculating. But once a boy reaches adolescence (assumed to coincide with a boy’s first ejaculation) he most normally ejaculates every time he has an orgasm.

Sources of first ejaculation are masturbation (two-thirds), wet dreams (in an eight of the cases), vaginal intercourse (one boy in eight) and homosexual contacts (one boy in twenty). Initially male arousal occurs as a response to hormones. Over time boys come to associate their arousal with psychological stimuli (erotic turn-ons) that are explicitly sexual. They also become increasingly reliant on specific penile stimulation for orgasm.

Some boys ejaculate when they are asleep. Wet dreams are most common (71% of men) between the ages of 21 and 25 when the highest average frequency is about once in three weeks (0.3 per week). By the age of 50 only a third of men have sex dreams, which do not average more than four or five a year. Both masturbation and sex dreams are more common among the educated because they depend on a man having a creative imagination.

Erection … is practically a daily matter for all small boys, from earliest infancy … Slight physical stimulation of the genitalia, general body tensions and generalized emotional situations bring immediate erection, even when there is no specifically sexual situation involved. (Alfred Kinsey 1948)