Whether or not twins are separated at school, a subject of debate that is often a dilemma for parents, has no affect on their grades, according to a Dutch study published Tuesday.
A team from Amsterdam's VU University based their finding on a study of 2,003 pairs of Dutch twins who were born between 1986 and 1993 and were followed by researchers until they reached 12, the study says.
The group was made up of 839 monozygotic, or identical, twins and 1,164 dizygotic, or false, twins, said the report published in the specialist review Journal of Epidemiology and Community Health.
By the time they were 12 years old, 72 percent had studied in the same classroom, 19 percent had been in separate but parallel classes and nine percent had shared the same classroom for only some of their schooling.
On reaching 12, the twins were put through a standardised Dutch test that assesses skills like language and maths but researchers found no significant difference in the results from the three groups.
There was also no important difference between the results from identical and false twins, or boys and girls.
The researchers also studied a smaller group to see if twins in the same class tended to have the same friends. They found they did but added this was not surprising as friendship at primary school is mainly with classmates.
"The choice of separation should be made by teachers, parents and their twin children, based on individual characteristics of a twin pair," the study concluded.