This report will consider adolescence as a stage of development. As Lefrancois (1995, p. 6) has noted, life span development psychology is "the discipline that studies changes that occur from conception through adulthood and that looks at the processes and influences that account for these changes." It is a relatively "new" area of interest, in which basic assumptions include a belief that development is continuous, that maturity is relative, that development occurs in context (vis-a-vis environmental and ecological factors and settings, such as the family), and that developmental influences are "bi-directional" or shaped by and shaping of social context or environment (LeFrancois, 1995).
Similarly, as Bee (1999) has commented, life span development encompasses recognition of the simultaneous effects of "nature" and "nurture" on the developing organism - in this case, the human child. Human "nature," expressed as gender, biology, genetics, and individualized skills and deficits, is but one influence on the developing child. "Nurture," or the environmental influences, includes culture, family, role models, and other influences found in the social and cultural setting in which the child is raised (Bee, 1999).
Jean Piaget, a Swiss psychologist, spent more than fifty years observing the behavior of his own and other children as they grew from infancy to adolescence (Bee, 1999). From these observations, Piaget constructed a theory of cognitive development that is based upon the assertion that mental growth is basically an increased ability to adapt to new situations. Nathan Isaacs has stated that Piaget identified two main keys to a child's mental growth. These are:
(i) the paramount part played from the start by his
own action (ii) the way this turns into a process of
inward building-up, that is, of forming within his
mind a continually extending structure corresponding to
the world outside (Isaacs, ...