This is something I told my three children growing up — if they jumped as high as they could once the clock struck midnight, the tallest height they reached would be how tall they will grow up to be.
Background: The informant is a 60 year-old Filipina immigrant to the United States. She told me that her mother told her and her own siblings the same tradition growing up. While she does not exactly believe in its practical use, it was a harmless and fun way of ringing in the coming growth in the new year.
Context: This belief was told to me during a weekly luncheon that always follows our Sunday church services.
Probably my favorite pieces in this collection are the rituals whose origins can’t really be traced, so it’s unclear how or why they came to be. But used now, they are just a cemented given in family situations as part of their experience of the culture. It’s unlikely that there is any real basis in the idea of freezing heights in time beyond the general folk belief, but most people nowadays just do them for the sake of novelty.