A long beard is a sign of a man's secondary sexual characteristics. The emergence of secondary sexual characteristics is stimulated by androgen secreted in the testis after men enter puberty. Before 1 1 years old, there were few androgens in boys, and there was not much difference in signs between men and women. There is no strict time limit for the puberty development of boys, which is generally from 10 to 14 years old.

After entering adolescence, the first sign is swelling of testis and scrotum. As the testis matures, it begins to have the ability to produce sperm and androgen. Under the action of androgen, male genitals develop rapidly and appear secondary sexual characteristics, such as strong body, muscular body, small shoulders and hips, long facial beard, raised Adam's apple and low voice. Men's beards are the result of androgen. There is also a process in the appearance and shaping of men's beards. Only when puberty is over, sex is mature, and the androgen in men reaches the level of normal adults, the beard will increase to the appearance of adults.

The level of androgen in healthy men is basically the same, but the number of beards varies from person to person. Some people have thick beards, while others have sparse beards; Some people have beards, others have goatees. These are the differences under normal circumstances. It is normal that the number and shape of beards are related to ethnic and family inheritance. Don't worry at all.

Whether a man without a beard is morbid depends on the whole body development. If a man has no beard, but his reproductive organs and the above-mentioned secondary sexual characteristics develop normally, it is not morbid. It is normal for boys to grow beards at different ages, some years earlier and some years later, so don't worry at all. If you have entered adolescence and have no beard, the secondary sexual characteristics are not obvious. Even after puberty, you are still undeveloped. This should be considered abnormal. It may be that there is something wrong with gonadotropin, which regulates the secretion of sex hormones, and it is necessary to go to the hospital for examination and treatment.

Psychologists tell you the role of men growing beards:

Beards flaunt confidence because they are inferior in battle.

In the book "Almost Principle" published by 1997, Israeli physiologist Avishag Zahavi and her husband, evolutionary biologist Amotz, proposed that the beard is a symbol of the extraordinary cost of male competitiveness, because it will be easily caught by opponents in fighting. According to this principle, the bearded man is obviously showing his strong physique: he thinks he can beat his opponent even with a beard!

Beards show a man's health.

Biologists william hamilton and Marlene Zucker.

Zuk) has a similar reasoning route. In a scientific paper in 1982, they suggested that bearded men are widely promoting that they have a healthy immune system. Beard, like other body hair, is a well-known breeding ground for bacteria. In recent years, they have been proved to be hosts of bedbugs and sand fleas.

Beards can protect the face from ultraviolet rays.

The idea that facial hair plays a role in regulating body temperature or shielding solar radiation was formed decades ago-dermatologists Valerie Randall and Ebling also supported this theory-and they also suggested that the growth rate of body hair varies with seasons: in summer, the growth rate of male beard is 50% to 60% faster than that in winter.