Chanting in Unison

What is it about chanting in unison that is so appealing and enjoyable to little kids? One child will start a comment, and the other child will join in, as they repeat the phrase over and over again.  This week's phrase seems to be "Go awaay, dude!" chanted as only a 3 year old and 5 year old can do.  I guess it's an improvement over "Trick or treat, smell my feet, give me something good to eat. If you don't, I don't care, I'll pull down your underwear".  This one is still frequently chanted, regardless of the fact that Halloween was 7 months ago.  I mean, really, is the a word that is much funnier to a 3 and 5 year old than "underwear"?  Who can blame them?

I guess as adults we're found chanting things in unison at sporting events or even political rallies.  So, maybe we don't ever grow out of it.  The things we chant, though, are maybe not quite so random.  It's like joining in singing when someone else is singing a song, I guess.  There must just be something inborn in us about being part of a group.