Scientific inquiry is encouraged, too. "Children are actively involved in formulating hypotheses, designing experiments, collecting and organizing data and drawing their own conclusions." Even though children at the pre-operational stage are egocentric and view the world as if it were solely their own, they still probe for answers and explanations about what they smell, hear, taste, touch, and see. Scientific activities also allow the children to witness cause and effect scenarios that enable them to develop appropriate cognitive skills. Those skills develop naturally in conjunction with verbal and mathematical thinking skills.

The Bank Street Head Start program loosely follows Piaget's theory of early childhood development. Children gradually and naturally incorporate new objects, experiences, and ideas into their cognitive schemas: the process Piaget called assimilation. Children also accommodate their old schemas...

Past the purely sensory-motor stage in which repetitive object manipulation is of foremost importance to the child, the pre-operational stage involves increased cognitive sophistication including the acquisition of language. Language, and its use in human communications, is a fundamental feature of the Head Start program. Similarly, the use of language to help children develop their natural inquisitiveness is one of the primary features of the Bank Street Head Start program. Creative play is a central method of learning at the pre-operational stage, and so the Head Start program does offer age-appropriate curricula. Each aspect of the Head Start program seems to uphold Piaget's principles of cognitive development.