The example above is called nakizumo, crying sumo. Here the referee is encouraging (frightening the living shit out of?) the babies, but sometimes they have versions (also called konaki zumo) where two sumo wrestlers each hold a child and turn them to suddenly face each other, thus making them yowl. The one with the loudest cry wins.
Babies are supposed to cry, evidently. I remember when J was just born my mother-in-law would say the longer a baby cried the stronger his lungs would become. I imagined her kids had some monster lung capacity to go with their diaper rash, hunger pangs and lonliness. I smiled and changed my kid's nappies reminding myself my mother-in-law said a lot of things. Believe me, I could write a book.
However, having a baby belt out a good one is an auspicious event. Well, kinda. I think I can speak for everyone when I say a toddler throwing a tantrum in the check out isle is far from auspicious. But when you consider that these festivals are hundreds upon hundreds of years old--back when a big cry was a simple way to determine a healthy, strong baby that would eventually grow into a healthy, strong adult, then it totally makes sense.
Every summer they have a big three-day festival in my town. Children aged one, two and three are allowed to participate in all sorts of fancy ways--prayers, parades, dances. Man, you should see their adorable little outfits (note to self: must scan old pictures).
The first event of the the festival (and only done once when the child is one) is called kami korogashi, or god rolling. The priests line up across from one another, two to a tatami mat, and are handed a child. They then chant prayers as they roll the child around and around until it starts to howl. Everyone laughs and claps and celebrates the wee one's fine pair of lungs as well as his continuing health and good fortune. It's a great photo-op, I tell ya.
I just remembered there is a Japanese saying, naku ko wa sodatsu, a child who cries grows/thrives. There is also one that goes, neru ko wa sodatsu, a child who sleeps a lot grows/thrives.
I've since gotten used to the tradition, but I must admit I was at first worried about the poor child's mental state.Then I saw this!
Cracks me up.