Skip to content

Tongue Rolling: Lies, I Tell You!

March 26, 2012

Yes, that's me, acting like a goofball.

I learned something neat the other day.

Think back to your high school biology class.  When you were studying genetics, your teacher probably told you that being able to roll your tongue is a dominant trait and not being able to roll it is recessive.  That’s not actually true.

There are pairs of identical twins out there where one twin can roll their tongue and the other can’t.

That by itself doesn’t mean that tongue-rolling isn’t genetic.  There are traits out there that are controlled partly by genes and partly by factors we don’t fully understand.  Schizophrenia, for example, is partly genetic.  Yet there are pairs of identical twins out there where one twin gets the disease and the other doesn’t.  Something about the environment triggers the disease in only one of the twins.

You’d expect, though, that if genetics has something to do with tongue rolling, then identical twins should be more likely to both be able (or unable) to roll their tongue than any other two people.  Scientists from the University of Adelaide in South Australia actually tested this way back in 1975.*  They surveyed 47 pairs of twins, some of whom were identical, about their ability to roll their tongue.  The result: the identical twins weren’t any more likely to both be able to roll their tongue than the fraternal twins.  The study didn’t find that genetics had anything to do with tongue rolling.



*  If you want to read the study, look here: Martin, N.G.  No evidence for a genetic basis of tongue rolling or hand clasping.  J Hered (1975) 66(3): 179-180.

4 Comments leave one →
  1. April 24, 2013 7:34 AM

    whoah this weblog is great i love studying your articles.
    Keep up the good work! You understand, many persons are looking around for this info, you could
    help them greatly.

  2. June 17, 2013 8:12 PM

    Hi! I’ve been following your site for some time now and finally got the bravery to go ahead and give you a shout out from Atascocita Tx! Just wanted to mention keep up the fantastic job!


  1. The Liebster Award | Steam Trains and Ghosts

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: