blank slate, or tabula rasa, to be formed by experience). The concept of maturation, which is central to developmental psychology, stresses the role of nature in human development. The interplay of nature and nurture, rather than the importance of one over the other, however, has gained a greater emphasis in the work of more recent figures, notably the Swiss psychologist Jean Piaget (Wood, et al, 2002, p52), whose theory of cognitive development in children has been a model for much subsequent work in the field.
             Another significant issue in the field of developmental psychology is the question of continuity versus stages, specifically; does an individual's development occur in a gradual and progressive fashion, or in a distinct series of discrete stages? In his pioneering theory, Piaget (Wood, et al, 2002, p52), delineated a sequence of developmental stages that occur in a fixed order with each dependent on the previous.
             In addition to Piaget, another major influence in the area of human development was Erik Erikson (Miell, et al, 2002, p54 & Wood, et al, 2002, p39-41, 42, 43) whose eight stages of psychosocial development, encompassing the entire life span from infancy through old age, inspired an interest in the continuation of development past childhood.
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