Women Who Shared Womb with a Brother Tend to Have Poorer Life Outcomes | By Benjamin Ryan | PHARMATIVE.com
A large study of Norwegians who today would be in their 40s and early 50s has found that women who shared their mother’s womb with a twin brother have lower rates of various metrics of success in life. In theory, being exposed to testosterone during gestation may have led such females to adopt certain male traits that society frowns upon among females, and that this difference among them ultimately held them back in life.
Publishing their findings in the Proceedings of the National Academic of Sciences, U.S. and Norwegian researchers analyzed data on 13,800 twins born in Norway between 1967 and 1978. They found that, compared with females who had a twin sister, females who shared a womb with a brother were 15.2 percent less likely to complete high school, 3.9 percent less likely to finish college, 11.7 percent less likely to get married, had a 5.8 percent lower fertility rate and earned 8.6 percent less.
It is possible that being raised with a twin brother socializes females differently and that this effect, not anything related to the prenatal period, could have driven the differences in life outcomes among these women. So, the study authors looked at a subset of females in the study cohort whose twin brothers died shortly after birth. There was essentially no difference in the various life outcomes among this subset compared with the overall cohort of females who had a male twin. This led the researchers to conclude that exposure to testosterone during gestation may indeed be the culprit.
The study authors stressed that their findings are specific only to Norwegians born during this time period. It is possible that in other countries with different gender norms, and as such norms evolve over time, women who doubled up in the womb with a brother would not see such compromised outcomes in life.
Additionally, these findings are averages, so they certainly do not indicate that all women who have a twin brother are destined to have a harder time in life.
Sources:
https://www.sciencedaily.com/releases/2019/03/190318151730.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_science+%28ScienceDaily%3A+Top+Science+News%29
https://www.pnas.org/content/early/2019/03/14/1812786116 #medicine#twins#research#pharmative
A large study of Norwegians who today would be in their 40s and early 50s has found that women who shared their mother’s womb with a twin brother have lower rates of various metrics of success in life. In theory, being exposed to testosterone during gestation may have led such females to adopt certain male traits that society frowns upon among females, and that this difference among them ultimately held them back in life.
Publishing their findings in the Proceedings of the National Academic of Sciences, U.S. and Norwegian researchers analyzed data on 13,800 twins born in Norway between 1967 and 1978. They found that, compared with females who had a twin sister, females who shared a womb with a brother were 15.2 percent less likely to complete high school, 3.9 percent less likely to finish college, 11.7 percent less likely to get married, had a 5.8 percent lower fertility rate and earned 8.6 percent less.
It is possible that being raised with a twin brother socializes females differently and that this effect, not anything related to the prenatal period, could have driven the differences in life outcomes among these women. So, the study authors looked at a subset of females in the study cohort whose twin brothers died shortly after birth. There was essentially no difference in the various life outcomes among this subset compared with the overall cohort of females who had a male twin. This led the researchers to conclude that exposure to testosterone during gestation may indeed be the culprit.
The study authors stressed that their findings are specific only to Norwegians born during this time period. It is possible that in other countries with different gender norms, and as such norms evolve over time, women who doubled up in the womb with a brother would not see such compromised outcomes in life.
Additionally, these findings are averages, so they certainly do not indicate that all women who have a twin brother are destined to have a harder time in life.
Sources:
https://www.sciencedaily.com/releases/2019/03/190318151730.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_science+%28ScienceDaily%3A+Top+Science+News%29
https://www.pnas.org/content/early/2019/03/14/1812786116
#medicine #twins #research #pharmative