With greater wealth comes lesser need to worry about costs like diapers, it seems. Or Western parents don't know how to whistle.
In the western world, babies now need diapers until an average of three years of age, nearly twice as long as 40 years ago. The situation in Vietnam is just the opposite. A study by scholars at Sahlgrenska Academy, University of Gothenburg, Sweden, followed 47 infants and their mothers in Vietnam, where potty training starts at birth and the need for diapers is usually eliminated by nine months of age.
The secret? Learning to be sensitive to when the baby needs to urinate.
"The woman then makes a special whistling sound to remind her baby," Anna-Lena Hellström says. "The whistling method starts at birth and serves as an increasingly powerful means of communication as time goes on."
According to the study, women notice signs of progress by time their babies are three months old. Most babies can use the potty on their own by nine months of age if they are reminded, and they can generally take care of all their toileting needs by the age of two.
"Our studies also found that Vietnamese babies empty their bladders more effectively," Professor Hellström says. "Thus, the evidence is that potty training in itself and not age is the factor that causes bladder control to develop."
Swedes have grown accustomed to the idea that babies cannot be potty trained, but that parents need to wait until they are mature, usually when they decide that they no longer want diapers. The evidence from Vietnam demonstrates that more sophisticated communication between parents and their babies would permit potty training to start and be completed much earlier.