It holds Colic to be a phenomenon of neurologic immaturity. It has been observed that infants with Colic are more easily over-stimulated than other babies. State-control is the neurological skill felt to be relatively immature in these babies. This ability, like memory or language, gets better with age. Most adults are far better at it than children.
Older children are better than younger children.
Some newborns are better at it than others. The neurodevelopmental theory is supported by several observations. The first is that all babies with Infant Colic outgrow it, usually by 4 months of age. In our experience, this works for many babies, but not all. It has the advantage over other potential therapies of being harmless, at least.