Tool selection based on rigidity in young children: a comparative approach (Seleccion de herramientas en funcion de su rigidez con ninos preescolares: un enfoque comparativo)

Fifty-one 23-to-55-month-old-infants faced two apparatuses that required the use of a rigid (box apparatus) or flexible (hose apparatus) stick-like tool to retrieve a toy stuck inside. Before attempting the extraction, however, they had to pick the only one tool (of three) on display that had the appropriate rigidity/flexibility to be effective. To inform their decisions, they could either manipulate the three tools themselves (haptic information) or observe the experimenter bending and unbending them for just five seconds each (visual information) before selection. Children found more difficulties in selecting appropriate flexible tools, as compared to rigid ones. Moreover, infants' own haptic inspection of each tool did not significantly improve their selection accuracy, which indicates that observing the experimenter's demonstration conveyed all the information required to make correct choices.