NO of course, not.
The proof is in the word "theory"; a theory is a set of beliefs consistent with evidence and facts. But a theory is, by definition, unproven. Moreover, old theories are always being revised, and replaced by more comprehensive theories. Theories may work very well to facilitate understanding and produce desired results. But a theory is unproven; if it ever is proven, it becomes fact and evidence, and no longer theory.
In every field of science, including the social sciences, we manage to make progress in understanding by developing theories that in themselves imperfectly describe underlying phenomena. Eventually, though, either every theory is proven, or must be modified or replaced; that's okay, because our imperfect theories let us make progress, all the same. Many theories are found to be special cases of larger theories (e.g., Newtonian physics is a special case of Einstein's work).
As for theories in the child development field, until every child that ever exists (and ever will exist) is thoroughly studied, we cannot say for sure that any currently popular set of theories can capture all the diversity of human development.
The current theories are still useful for most children, we just have to be open minded about kids who don't/can't/won't fit neatly inside the existing boxes.
The proof is in the word "theory"; a theory is a set of beliefs consistent with evidence and facts. But a theory is, by definition, unproven. Moreover, old theories are always being revised, and replaced by more comprehensive theories. Theories may work very well to facilitate understanding and produce desired results. But a theory is unproven; if it ever is proven, it becomes fact and evidence, and no longer theory.
In every field of science, including the social sciences, we manage to make progress in understanding by developing theories that in themselves imperfectly describe underlying phenomena. Eventually, though, either every theory is proven, or must be modified or replaced; that's okay, because our imperfect theories let us make progress, all the same. Many theories are found to be special cases of larger theories (e.g., Newtonian physics is a special case of Einstein's work).
As for theories in the child development field, until every child that ever exists (and ever will exist) is thoroughly studied, we cannot say for sure that any currently popular set of theories can capture all the diversity of human development.
The current theories are still useful for most children, we just have to be open minded about kids who don't/can't/won't fit neatly inside the existing boxes.