If a man has more brothers than sisters, he is more likely to have a boy, and the greater the proportion, the greater the probability. Conversely, if there are more sisters than brothers, there will be more girls than boys. Because it is the man who has the final say in having boys and girls, we mainly observe the man's family.

2. Having boys and girls is related to personality.

The man's character, slovenly, rough, does not like to do housework, mostly male. If a man likes cleanliness and delicate personality, most of them have daughters. Strong female mothers who often give orders and are in power are more likely to have boys because their male hormones are stronger. And quiet and docile mothers have more girls. If the mother has a strong dominance, the male hormone in the egg is high and she is good at accepting the Y chromosome in the sperm.

3. Giving birth to boys and girls is related to the conception environment.

The most important indicator of pregnancy environment is the PH value of the woman's body. If the pH value of the pregnant environment provided by the woman is strongly alkaline, the probability of giving birth to a boy will greatly increase, and vice versa.

4. Having boys and girls is related to eating habits.

If the diet tastes big, the chances of having a boy will increase, and if it is light, the chances of having a girl will increase.

Giving birth to boys and girls is related to physical labor.

Women's physical labor intensity is low, and the chances of giving birth to men increase. The greater the intensity, the greater the chance of giving birth to a woman. Therefore, having children after marriage for a period of time, if the wife often cooks, will reduce the leading role of the man in giving birth to boys and girls. The consumption of diet and physical strength constantly changes the pH of the woman's body, affects the environment of pregnancy, and also affects the pH of the man's body and the production of male sperm, so this is very important.

6. Boys and girls are determined by Y chromosome.

The female sex chromosome is XX genotype, and the male sex chromosome is X and Y genotype. Y sperm and egg combine to be a boy, and vice versa. The probability of combination is naturally random, but there are still some rules to follow. Although the birth of boys and girls is determined by Y sperm, it will also be affected by many factors.

7. The acidity and alkalinity of boys and girls are related.

We know that when women are in the safe period, the milk in the cervix will become thick and acidic; During ovulation, the emulsion is dilute and alkaline, which makes the sperm pass smoothly. However, some women will still be acidic during ovulation. At this point, when they share the same room, X sperm can barely pass, while Y sperm will die halfway. At this time, it is more likely to have a girl.

These are all related.