Twins in the U.S

Twins are a natural phenomenon that is occurring more and more frequently in the U.S. as a twin personally I chose to research various statistics and information on twins in the U.S and found some interesting research conducted outside the U.S.
Firstly, there are 2 types- monozygotic (identical-1 zygote) or dizygotic (fraternal- 2 zygote). Some twins may be called “mirror twins” which means opposite facial features and opposite dominant hands.
I found an interesting study outside the U.S: Village of Kodinhi study-”Baffled doctors are trying to unravel the mystery of an Indian village boasting more than 220 sets of twins born to just 2,000 families. Experts who have visited the remote tropical village of Kodinhi, in Kerala, have been left scratching their heads over the phenomenon that has seen almost six times as many twins born than the global average. In 2008 alone 15 pairs of twins were born in the village out of 300 healthy deliveries and this year is expected to top that number.”
Various researches showed that the 2007 twin birth rate was 32.2 per 1,000. This remained unchanged from 2005 and 2006. (United States) The number of live births in twin deliveries rose 1.3 percent between 2006 and 2007 to 138,961 births. This number has more than doubled since 1980 (from 68,339). I also found various researches on twins and other ethnicities:
Non-Hispanic White: 36.2 per 1,000
Non-Hispanic Black: 36.8 per 1,000
Hispanic: 22.2 per 1,000
For the years 2005- 2007, twins accounted for more than 4 percent of all births (more than 40 per 1,000) in Massachusetts, Connecticut and New Jersey. New Jersey, Nebraska and Massachusetts also recorded the highest rates of higher order multiple birth (triplets or more). The lowest rates were reported in New Mexico.
A study conducted in Denmark observed a set of twins (3411) comparing them to “singletons” (7796) and found that through adolescence their academic achievement was not lower (even compared to low birth weight). However earlier studies (Taiwan) of older twins showed that math, and science scores were lower than that of singletons and that they had a lower probability of attending college, and if their birth weight was significantly low the probability of attending college was even lower. Minnesota was the first state to allow parents to choose if their twins can be in the same classroom (2006). Until then it was law that they had to be separated. However some professionals had opposing views: “Twins are never 50-50 in their skills and abilities,” said Stuart Goldman, an assistant professor of psychiatry at Harvard Medical School who also works at Children’s Hospital Boston. “You want them to develop skills and competencies on their own.” To combat that I found a quote supporting the idea of twins in the same classroom:…”Many people may think this might be micro-parenting . . . but this idea that twins won’t be individuals if they stay in the same classroom is so misguided and not based on research,” said Nancy L. Segal, a psychology professor and director of the Twins Studies Center at California State University, Fullerton. Furthermore, personally I feel that twins should be allowed to be in the same classroom, I feel separating them does not take away their own identity and until more recent research is found they are fully capable of doing well academically in the same classroom or even separate just as well as singletons.

http://twinstwice.com/twins.html
http://www.independent.co.uk/news/education/education-news/maths-agrades-for-nineyearold-twins-2056945.html
http://newsone.com/nation/good-news-nation/casey-gane-mccalla/twin-girls-with-identical-grades-become-joint-valedictorians-of-high-school/
http://multiples.about.com/od/funfacts/a/twinbirthrate.htm
http://psychcentral.com/blog/archives/2008/07/27/massachusetts-legislators-are-asking-should-twins-always-be-separated-in-the-classroom/
http://www.usatoday.com/news/education/2008-07-20-college-twins_N.htm
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2500195/
http://www.bmj.com/content/333/7578/1095.abstract
http://www.sciencedirect.com/science/article/pii/S1084275602901090
http://www.sciencedirect.com/science/article/pii/S000293789770334X
http://www.nytimes.com/2006/02/24/national/24twins.html?pagewanted=all
https://www.revisor.mn.gov/revisor/pages/search_status/status_detail.php?b=House&f=SF0180&ssn=0&y=2005
http://www.twinsmagazine.com/twins%E2%84%A2-magazine-facts-statistics-regarding-multiples