A recapitulation of criticism against the theory of childhood
The theory of childhood, also known as child origin, is a damnable, loathsome and indefensible lie. How can any thinking person suppose all humans used to be babies once? Just consider these arguments:

There is no development path from babies to adults, no transitional forms between these two species. Show me even one baby with the head of a grown man on his body. Can you? No? Not even a bearded toddler? No adults with unfused skullbones, outside unfortunate disorders? Not even a tiny little newborn girl suddenly sprouting a respectable bosom? You can't find them, because they don't exist. There isn't a single transitional form between children and adults, and you will never find one because the theory simply is an unscientific lie.

The development of children has been well-researched in our six-month study following a sample of one thousand children and adults of various ages. We have conclusively proven that while there are minor changes in features like height and body fat, and replacement of deciduous teeth with permanent teeth, incontravertibly still every creature in the study that started out as a child had only slightly more adult features at the end of the observation period than at its beginning. Children and adults are separate kinds and there will never be sufficient changes to change one into the other. We reject any evidence from longer-term studies as we believe the laws of physics have changed within the last year.

To claim people come from children is demeaning and morally degrading. We have observed how children behave. If we acted like small children we'd all be demanding and impatient, and we'd be cheating, lying, and stealing from each other all the time. If the theory of childhood were true there would be no morality, and with no morality to build one on, no society. Childhood is a wicked lie used by charlatans to justify evils such as public schools.

There is no consensus on the theory of childhood in the scientific community. We should teach the controversy. Our children will be served well to learn that the prospect of them becoming adults is merely a theoretical idea. Many children come from families that do not subscribe to the theory of childhood, and they could be disturbed if the theory were taught as fact.