"The researchers found that out of the 1302 parents, 191 (14.7%) were misinformed about their same sex twins' zygosity (identical or non-identical)."
That sure is a lot of mislabeled twins. It seems that in this day-in-age, it would be a lot easier to figure this out but doctors are still getting it wrong pretty regularly.
Another thing that makes us, as fraternal twins that look a ton alike and sound exactly alike, go HMMMMmmmmmmm. Maybe they were wrong about us too.
To read more about the findings in this research, go to
Are my twins identical? http://www.sciencecodex.com/are_my_twins_identical-86918