Developmental psychology aims to produce scientific explanations of the behavioural and psychological changes that children undergo during their lifespan. Some of the theories produced in this research field focus on specific aspects of development, such as language or sensory development, while others, known as grand theories (The Open University, 2006b), are interested in finding general explanations for development. This essay will present an overview of one of the most influential grand theories in developmental psychology, constructivism, proposed by Swiss theorist Jean Piaget. It will specifically focus on the concept of conservation, a cognitive ability acquired by children in the course of their psychological maturation, and on the experimental tasks through which he tested his predictions. Finally, it will critically evaluate Piaget 's conclusions by examining a series of alternative versions of the conservation tasks and will discuss, through the lens of alternative explanations proposed by his major critics, how simple variations in methodology have produced conflicting evidence.
Born in Switzerland in 1896, Jean Piaget (The Open University, 2006b) is known as one of the most influential contributors in the field of developmental psychology. His theory of cognitive development originated from a series of observations conducted in 1920, while working as a translator of intelligence tests in Alfred Binet 's laboratory. Noticing that children tended to give systematic wrong answers, he suggested that these errors revealed a fundamental, qualitative difference in children 's cognitive abilities, and found confirmation of this hypothesis in observations of his own children. Is this relevant? It
References: Holah (n.d.) Samuel and Bryant (conservation) Study [Online]. Available at http://www.holah.co.uk/study-detail.php?slug=samuelbryant (Accessed 09 March 2013). The Open University (2006a) ‘Media Kit’ [DVD], ED209 Child Development. Milton Keynes, The Open University. The Open University (2006b) Psychological Development and Early Childhood, Milton Keynes, The Open University.