Which educational psychologist believed in the fact that “All children have…

Some theories of learning hold that every child already possesses an innate capacity to learn and grow, and that this capacity is present from birth rather than something instilled from outside. On this view, education's task is not to pour in knowledge but to provide the right nurturing environment - especially structured, guided play - so that the capacity already inside the child can unfold naturally.

This is exactly the belief quoted in the question - “All children have the potential to learn.” It is the founding premise of Friedrich Frobel's kindergarten movement: Frobel treated the child like a seed whose inherent capacities need only the right conditions - his specially designed play materials and guided activities - to develop. He built his entire kindergarten curriculum on the conviction that no child is incapable of learning, which is why the exam key marks Friedrich Frobel as the psychologist associated with this belief.

Checking the other named educators against their own well-known contributions confirms none of them is the source of this particular claim:

• John Dewey's philosophy of education centres on learning by doing - engaging in purposeful, real activity as the process through which experience is continuously reconstructed into knowledge.

• Johann Friedrich Herbart formalised teaching into a sequence of clear steps - presenting material, connecting it to prior ideas, generalising it into a system, and applying it - as the method for building sound moral character in students.

• Maria Montessori's method centres on self-directed activity within a carefully prepared environment, timed to each child's naturally occurring sensitive periods of development.

Friedrich Frobel is therefore the psychologist who believed that all children have the potential to learn.