1. Hair
Everyone knows that Irish Dancers have curly hair, but what some of you may not know is that they are wearing wigs. You'll see these girls carrying hundreds of bobby pins to keep their wigs on, even if they only have a bun wig. One of the easiest ways to know that those bouncy curls are only part of a wig is by looking at the crown of the head for either a fold in the hair, where the wig begins, or by seeing a headpiece that blocks this separation between the real hair and the wig from being seen.
2. Footwear
Irish Dancers will either wear their soft shoes, or ghillies, or their hard shoes. Younger dancers will be seen wearing poodle socks, some of which are bejeweled, while adults more often where black tights.
3. Arm Position
Here is one of the major differences between Irish Dancers and Scottish Dancers: the use of arms. In solo dances, Irish Dancers keep their arms down by their sides. In fact, points are taken off a dancer's score if they move their arms too much during competitions. The only time Irish Dancers would use their arms in a routine are during Ceili dances, where they dance with one or more partners. Scottish Dancers often keep their arms up, similar to a Ballet Dancer only with their thumb and middle fingers touching, or with one or both hands in fists on the hips.
4. Knees
Another major difference between Irish Dancers and Scottish Dancers is the way in which they dance with their legs. Crossing their legs so that only one knee can be seen at a time is critical to an Irish Dancer's form. Scottish Dancers dance with their knees apart and out to the sides.