Recently, I took my son out to play, and I heard a very interesting saying: a father is more likely to give birth to a daughter when he gives birth to his first child, while a mother is more likely to give birth to a son when she is wise. Sex is greater. I was surprised when I heard that my eldest son had given birth to a boy. Doesn’t it mean that I have a very high IQ and put pressure on my child’s father? But thinking it through is not the same thing. Looking at the editor's doubts, this hot mother gave a few examples: Don't believe it when you look at Robin Li, Kaifu Li and Xu Yan, Huang Bo, and even the "magic fortune teller" Huang Lei have two daughters. The gender of the child is really related to Does the IQ of parents matter? Searched the internet for a lot of words. Indeed, as hot moms say, many famous eldest sons have daughters. But is this rumor or science? I remember a famous saying from some time ago: "Other people are full-time spreading rumors, but I am only part-time in science popularization." In the spirit of conscientious science popularization, let me talk about gender and IQ.

Biologically speaking, whether a boy or a girl is born is mainly determined by sex chromosomes, more precisely, by the sex chromosomes of the man. Sex chromosomes, as the name suggests, are the chromosomes that determine gender. In human germ cells, there are 23 pairs or 46 chromosomes, of which 22 pairs are autosomes and 1 pair is a sex chromosome.

The female chromosome is XX and the male dye is XY. After two meiotic divisions, the germ cells change from 23 pairs of chromosomes to 23 pairs. Eggs contain only one type of sex chromosomes, and sperm can contain X or Y sex chromosomes respectively. When the sperm unites with the egg, the fertilized egg's chromosomes return to 23 pairs. If a sperm containing an X chromosome is combined with an egg, the fertilized egg will be type XX and develop into a baby girl. If a sperm containing a Y chromosome is combined with an egg, the fertilized egg is XY and develops into a male baby. Therefore, the birth of a boy or a girl depends on whether the sperm is an X or a Y sperm. Currently, there is no scientific basis to prove that smart people have more sperm on the Y chromosome than on the X chromosome.

On the one hand, different IQ scales measure a person's different abilities, so IQ scores obtained using different scales are inconsistent and not comparable. On the other hand, IQ is unstable throughout a person's life, with the peak of some abilities occurring in middle age. Some abilities decline more quickly with age, while others decline more slowly with age, so IQs measured at different times are also unstable. In other words, neither parent can determine which person has the higher IQ, nor can the person with the higher IQ determine which sperm will fertilize. Therefore, from a scientific point of view, the statement "It is easier for a father to have a daughter when he has his first child, and it is easier for a son to have a son when he is smart" is incorrect. Next time you hear "parents' IQ affects the gender of their children," you might as well answer directly: Hawking and Li Ka-shing both gave birth to a boy. The statement itself is interesting.