Start with what the evidence does not say
It is routinely claimed that pretend play is essential to healthy development. When Lillard and colleagues reviewed that literature in Psychological Bulletin, they tested the claim against two rival explanations: that pretend play is one of many routes to the same outcomes, and that it is a by-product of other things that actually drive development.
Their conclusion for language, narrative and emotion regulation was that the evidence available is consistent with all three positions and insufficient to choose between them.
What shared stories more reliably do
The evidence is stronger a step sideways from pretend play. Hutton and colleagues scanned three- to five-year-olds while they listened to stories and found that greater home reading exposure was associated with activation in brain regions supporting mental imagery and narrative comprehension, controlling for household income.
That is a narrower claim than "stories build imagination", and a more defensible one: children with more story exposure appear to do more internal picture-building while listening.
Why children ask for the same story again
Novelty is not the engine people assume. Horst, Parsons and Bryan found that three-year-olds retained new words when the same storybook was reread, and performed at chance when the same words arrived inside different books.
So the child asking for the same story for the ninth night is not stuck. They are doing the thing that works, which is also why repetition settles bedtime.
A world leaves room that a moral closes
A moral hands over the answer. A world poses a situation and leaves the child somewhere to stand in it. That difference is about narrative design rather than developmental science, and we would rather say so plainly than dress it up as a finding.
What a consistent world does offer is a stable place to return to, which matters more for how a story is remembered than for how clever it is — see what children remember years later.
Open stories, consistent worlds
Openness is not the same as chaos. A world that changes its own rules each night gives a child nothing to build on.
Bajkos keeps the world consistent and lets the child move inside it. That is a design choice we can defend on narrative grounds, and we will not claim more for it than the research supports.
What this means for tonight
You do not need to pick stories for what they are supposed to develop. Pick one world, go back to it, and let your child move around inside it.
If they ask for the same one again, that is the mechanism working rather than a rut — and it is the most solidly evidenced thing in this article.