WILL GENETICISTS MANAGE TO UNRAVEL THE MYSTERY OF GENDER, INTELLIGENCE, AND TALENT?

Consultant at Jansen Capital Management

WILL GENETICISTS MANAGE TO UNRAVEL THE MYSTERY OF GENDER, INTELLIGENCE, AND TALENT?

Photo by Francesco on Unsplash

Apparently, so as not to offend either parent, science tends to assume that heredity is equally influenced by both the father and the mother. In reality, this common belief differs somewhat from how things actually are. And if you are concerned about what the sex of your future child will be, nature has prepared quite a few surprises for you there as well.

WHAT WE INHERIT FROM OUR MOTHER

here is a set of genes that are inherited through the maternal line. You will always owe your mother your body type, as well as whether you are left- or right-handed. Your mother’s predisposition to such conditions as cancer, diabetes, asthma, varicose veins, and psoriasis will not pass without a trace either. Her athletic aptitude also matters, since a mother passes on to her child DNA that helps produce a large number of oxygen-carrying cells during physical exertion. If a mother has strong «sports genes», the child’s physical endurance and chances of a sporting career increase significantly.

WHAT WE INHERIT FROM OUR FATHER

A father’s contribution is, naturally, no less significant. His genes are concentrated in the limbic system of the brain, which regulates our mood and instincts. Height, dental health, reproductive disorders, and cardiovascular diseases are also most often inherited from the father. At the same time, science cannot determine exactly whose genes a child has more of—maternal or paternal. Although some studies have noted a slight imbalance in favor of paternal genes, overall, there is still considerable confusion among scientists on this issue.

INTELLIGENCE DOES NOT DEPEND ON GENDER

The point is that autosomes — that is, all chromosomes except the sex chromosomes—are exactly the same in men and women. There are 22 of them, and they are responsible for most of the body’s traits. Intelligence is also determined by them, not by the sex chromosomes. Cognitive ability and gender are not linked, so it is impossible to say whether you inherited your «brains» from your father or your mother. However, it has been established that fathers can pass on intelligence only to their daughters, and only up to 50%. Maternal genes determine the quality of cognitive functions within a range of 40% to 60%. Overall, scientists tend to believe that high intelligence is not an innate trait, but an acquired one.

LOVE IS THE SOURCE OF INTELLIGENCE

The maternal contribution at a certain stage of a person’s life proves to be extremely important, since the development of intellectual abilities is influenced precisely by the emotional bond with the mother. If from early childhood you were surrounded by her love and care, you can be sure that your hippocampus will, on average, be 10% larger than that of children whose mothers were more restrained in expressing such feelings. And together with a more developed hippocampus, you will gain excellent memory and concentration. Studies have shown that those prodigies who were able to solve complex symbolic tasks as early as the age of two spent the greatest amount of time in close contact with their mothers.

GIVE BIRTH UNTIL THE FIRST BOY?

It is far from possible to «preprogram» everything in your future child. However, one can try, for example, to increase the likelihood of having a boy or a girl. According to data published in Science Advances, in families with three boys, the probability that the next child will also be a boy is 61%. In families with three girls, the chance that the next child will be a girl is 58%. That is, the probability that the sex of the next child will differ from that of the previous one is well below 50%. This allows us to take a different look at the tradition that exists in some cultures of «giving birth until the first boy».

IN LARGE FAMILIES, CHILDREN ARE MORE OFTEN OF THE SAME SEX

Of course, in patriarchal tradition it is most often the man who is regarded as the continuer of the family line, ensuring the continuity of generations, the preservation of historical memory, and so on. However, if the first child in a family is a girl, you may well never get an heir. Moreover, the more persistently you try, the more likely it is that your chances of obtaining the desired result will decrease. Harvard researchers studied the sex of children born to 58,007 women between 1956 and 2015 and found that in families with three or more children, siblings of the same sex occurred much more often than in families with only two children.

DOES A CHILD’S SEX DEPEND ON THE MOTHER’S AGE?

In addition, the mother’s age also turned out to be important for the sex of the future child. Among women aged 29 and older, the probability of giving birth only to boys or only to girls was 13% higher than among women under 23. That is, if you gave birth to a girl for the first time after the age of 29, then the second and third children are also likely to be girls. And, of course, genetic predisposition plays a role here as well: changes in one of the genes on the 10th chromosome increased the likelihood of having girls, while changes on the 18th chromosome increased the likelihood of having boys.

SO WHERE DO BEAUTIES AND GENIUSES COME FROM AFTER ALL?

At the same time, scientists honestly warn that the results of these studies cannot be used to predict a child’s sex, since they explain tendencies only at the group level. Thus, the mysteries of sex, beauty, intelligence, and talent remain not fully unraveled by modern geneticists. Perhaps, indeed, our children receive something from somewhere above?

Original research: