Before there were washing machines to process cloth diapers, let alone disposable diapers, children in Western societies were toilet trained significantly earlier than they are now, usually by around a year old. Similarly, the great majority of children today living in non-Western societies are also toilet trained by a year. The pattern largely reflects parental convenience; age at toilet training has increased in societies in which the ease of diapering has increased. A Chinese colleague of mine has noted that as disposable diapers have become more readily available in China, toilet training is becoming delayed there as well.
This is all quite understandable. There are many time pressures on parents, and the multitude of choices we make every day about child-rearing will inevitably factor in parental needs. There is nothing wrong with this; those who advocate a purely child-centered approach to child rearing can end up with extremely self-centered children who will have trouble functioning in the real world. And a parent who never considers her own needs can end up stressed in a way that impacts a child negatively.
The problem with current toilet-training philosophy is that choice has essentially been removed by the mainstream media and medical establishment. In the U.S., we now live in a world in which it does not occur to most people to train their children early, even though it is common practice elsewhere. Why is this so?
Early toilet-training advocates such as Dr. Linda Sonna and Laurie Boucke (see references below) have traced the current late-training trend mainly to a paper published in the journal Pediatrics by Dr. T. Berry Brazelton, who was famous for a time for his child-rearing advice. This paper (Brazelton, T.B., 1962. A child-oriented approach to toilet training. Pediatrics 29:121-128) became the basis for the now widespread idea that early toilet training causes psychological damage to a child, despite the fact that Brazelton's research was supported by Proctor & Gamble, which produces Pampers. (Back then it was not required to report conflicts of interest in a published paper, so there is no hint of the affiliation in the original version.)
The problem with the paper is that it essentially sets up a straw man; Brazelton compares punitive and coercive techniques used by advocates of early training in the early 20th century, known then and now for potential damage, to waiting until a child is 2 before initiating toilet training. This is an apples and oranges comparison, because he does not examine the outcome of non-coercive early training, which is used successfully by most people around the world.
An underlying assumption of Brazelton's paper, one that is still commonly believed today, is that children do not have voluntary control of their sphincter muscles until they are 18 months or older. Anyone who has had a toilet-trained 10-month-old can tell you that this is simply untrue. What Brazelton and today's "experts" ignore is the fact that babies have been trained since birth not to exercise control, because they are wearing diapers and their parents do not care where or when they urinate or defecate. Brazelton asserts without any basis that "there is little innate in the child that leads him to want to be clean and dry" when in fact there is strong evidence from babies who are never diaper trained that in infancy they do have an instinct not to wet their bedding or clothes, and they do alert their caregiver that they need to go. Again, babies that have been in diapers for a few months lose this awareness of their bladder and bowel.
The most absurd statement Brazelton makes, which reveals his narrow agenda, is the following: "The developmental energy invested in learning to walk on his own is freed after 15 to 18 months and can be transferred to the more complex mastery of sphincter control and toilet training." According to Brazelton, we must wait to toilet train until age 2 because learning control of two muscles, one each controlling bladder and bowel release, is more complex than learning to walk, which involves the use of dozens of muscles.
The paper was essentially instruction for doctors on how to brainwash parents not to toilet train their children when they wish to, but to wait until a child is about 2 and is physiologically "ready," based on his incorrect assumptions. In the intervening decades, this idea of "readiness" has been transformed to mean, in the mainstream media, that your child will decide one day that she wants to be toilet trained. Some parents are lucky enough that this indeed happens. For many however, toilet training is a struggle because after being conditioned for 2-3 years that the place to urinate and defecate is the diaper, the child is told that he must forget this conditioning. You try the reverse right now, as you sit reading: urinate in your pants, just as an experiment. Can't do it, can you? Conditioning is a powerful behavioral control.
Disposable diapers are indeed a convenience, really a luxury. Cloth diapers are viewed as more environmentally correct, but their use generates many gallons of wastewater, as well as quantities of detergent and bleach released into the environment. Parents should be aware that there is indeed a third option: eliminating the use of diapers as early as possible. At a minimum, I strongly recommend bowel training, which we achieved almost instantly with our daughter at 9 months when we gave her the opportunity to sit on a potty at the appropriate time. The methods for this are fairly straightforward, and are discussed in detail in the recommended books below. There are also resources available at the Elimination Communication store. For some it is a matter of convenience to wait until their child can complete the whole toilet process by himself. But it also takes time, a lot of money, and produces a lot of waste to change diapers for years. All pediatricians should make parents aware that non-coercive early toilet training is a choice that many families make successfully.