First of all it is important to know the difference between Irish STEP DANCING and SET DANCING.
Step dancing can be done individually or in a line, or in a two,three or four-hand reel.
The hands are held by the side except when linking in the figure dances.
In competition, if they move their arms they are disqualified, except in céilí competitions.
Set dancing is done in figures of 4, 6, 8, or longer lines. The dancers hold hands, and swing holding one hand, with the other hand on the partner's waist.
There are so many stories about why the arms are straight down in step dancing.
If you walked past a house and saw the top half of Irish dancers, it would be obvious they were dancing, so that doesn't fly.
It wouldn't make any sense to ban touching in step dancing, but not in set dancing, which has been around longer! No, I don't think it was the chastity police.
Some of the best dancers I knew were priests and nuns.
Here is a quote:
"The most believable theory, which is supported by many historians of Irish dance, is that the dance masters of the 18th century were responsible. They liked etiquette, and disapproved of the unruly arm movements of Sean Nos dancing. They therefore made their students dance with their arms in a fixed position, holding a stone in the hand to keep them in a fist."A more practical reason for keeping arms by their side was the size of Irish homes.
The small cabins and cottages often housed large families, and there simply would not be room to fling one's arms around.
Michael Flatley is a Showman, as well as a dancer.
So in Riverdance and his other shows, he and the principal dancers used expressive arm movements, to add some drama.
The following clip is not of the dramatic dance steps of Riverdance, these are the traditional steps required in Competition.
These young ladies are not dancing together,they are being judged individually at the All-Ireland Championships a few years ago:
http://www.youtube.com/watch?v=LC08VEyTGdA&feature=related
Here are young dancers at the fleadh cheoil 2007 doing a set dance:
(we do this one at our céilí)
http://www.youtube.com/watch?v=n-CxyXwWvoI&feature=related