why do they call it that?

I was having a conversation today with the young lady who cuts my hair and we got on the subject of school dances.  My granddaughter will be attending her first school dance next week and we got to talking about what dances were like when we were in jr high and high school.  We both agreed that younger boys seldom want to dance and that often clumps of girls gather in one area while boys gather in another - never the twain to meet.  I mentioned that in my day (I'm at least 30 years older than my beautician) we called them sock hops because we couldn't walk on the gym floor in our street shoes so we danced in our socks.  She said she had heard of sock hops all her life but didn't know that was how they got their name. I think that's how they got their name.  That's how I remember it. Does anyone have a different idea?