5 times long!"Two children" put pressure on "boss"

Text ｜ Li Muzi

Picture source: pixabay

The birth of the second child is not only an extraordinary experience for parents, but also for his brothers and sisters.

Human behavior research shows that a series of changes in the family will cause confusion and tension for the first -time children for a period of time, and they will become sticky, depressed and irritable.

So far, scientists don't know how much this pressure can be detected physiological.

VERENA BeHringer is a scientist at the Leibniz Lingye Research Institute in Germany. In a study co -conducted with the Candrard Lorenz Institute and an international research team with the Austrian Vienna Veteran University of Veteria, they checked various marks in wild chiriuria urine.

Researchers have found that the birth of the second cub will lead to 5 times increased cortisol of elderly brothers and sisters, and the immune response will decrease.

In addition, this physiological change has nothing to do with the weaning process of young animals with age. Related research results were published on Elife on August 30.

The research was conducted at the LUIKOTALE Research Station of the Congo Rain Forest. Two chira orangutan groups lived near the wild research station.

In more than 650 hours, the researchers observed the behavior of 17 small animals that became "brothers and sisters" for the first time -they were between 2 and 8 years old when their younger sisters were born. At the same time, the researchers also collected 319 urine samples before and after the birth of his brother and sister.

"With the growth of young animals, various processes of weaning or changes in food will also stimulate stimulus reactions."

Behringer said. Scientists analyzed the concentration of three different substances in urine samples: cortisol, neohlutin, and triaxytopicine (T3). Corticol is a hormone secreted by stress; new butterin is produced by the activation of the immune system; T3 is a thyroid hormone that regulate metabolic activities in the body.

Studies have shown that when the younger brother and sister are born, the level of cortisol in the urine of the "brother and sister" increases by 5 times, and this level is maintained in 7 months. The reaction is reduced; the thyroid hormone T3 has not changed significantly.

"The young chrome suddenly experienced an extremely stressful state when his brother and sister were born." Behringer explained that "cortisol levels are extremely high for a long time, whether the child is 2 years old or 8 years old. This continuous stress response has a negative effect on immune defense. Because the concentration of thyroid hormones has not changed, we can assume that the stress reaction is not stimulated by high energy pressure sources, such as sudden stop breastfeeding. "

The record data of the record also confirms this assumption. For example, researchers have observed the degree of breastfeeding "brother and sister", how much physical contact with their mother, and the frequency of being held.

All the weaning process that can appear as an extra stress source is either completed before the birth of the younger brother and sister, or it has not changed suddenly at birth, or it is more significant in young individuals, and it disappears with the growing up of young chrome.

"For the first time, our research shows that the birth of my brother and sister is a truly stressful event for my brother and sister." Behringer concluded, "But there is no need to worry. This pressure is tolerated and may lead to years. Long brothers and sisters have higher pressure resistance in the future. After all, younger brothers and sisters are not only competitors, but also important social partners. They have a positive impact on individual growth. "

Related thesis information:

http://doi.org/10.7554/elife.77227

"China Science News" (2022-09-09 No. 2 Edition International)

Edit | Zhao Lu

Capture | Zhihai

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