Human growth and development across the lifespan

Human Development Overview

One of the most intriguing and yet elusive areas of inquiry in the science of psychology is the cognitive and/or psychological development of the human being. There are many different theorists that have come to prominence in this field, and at least as many theories regarding how individuals develop, but there are enough similarities and commonalities between the most lasting theories that enable certain generalizations to be made about human development. In very broad strokes, for instance, there are three basic aspects or domains into which the various categories and stages of development can be divided: physical, cognitive, and psychosocial (Papalia et al. 2004). The three domains are, of course, highly interrelated, but basically the physical refers to the actual growth and development of the body and brain, the cognitive domain is concerned with how information is perceived and processed, and the psychosocial aspect of development deals with senses of identity and relationships with others (Papalia et al. 2004). All theories of development take these three domains into account.

All theories of development also divide human development into separate and distinct stages. Though there is disagreement about what to label these stages and their exact start and end points, a basic acceptable division of the stages of human development includes the prenatal period, infancy and toddlerhood (lasting to two or three years of age), early childhood, middle childhood, adolescence, young adulthood, middle adulthood, and late adulthood (Papalia et al. 2004). Most of these divisions are fairly self explanatory, and the lines between them tend to blur. The transition from early to late childhood takes place around sevn or eight years of age, adolescence begins with puberty, and the stages of adulthood are even more individual in the timing of their beginnings and endings (Papalia et al. 2004).

The many different theories of human development can be broken into several overarching categories. One of the most prominent of these is the psychosexual group of theories, most famously proposed and developed by Sigmund Freud (Newman 2007). This type of theory places a large emphasis on the early years of development, which (according to these theories) can affect and even dictate the later development of an individual (Newman 2007). Freud especially placed an overwhelming emphasis on infant and early childhood sexuality as the determining factor for later development (Clifton 1995). Erik Erikson agreed with some of Freud's analysis of development, but allows for greater changes due to upbringing and theorizes a basic, unique, and unalterable template that each individual starts life with (Clifton 1995).

Other theories, such as evolutionary theories of psychology and development, are based much more strictly on biological hard-wiring. Evolutionary psychologists believe that the brain should be viewed as an organ adapted to provide effective responses to specific survival situations, and that this can account for the modern developmental patterns (Newman 2007). This is often considered a highly impersonal and therefore largely imprecise and impractical framework for viewing development, especially since the purported events which have supposedly shaped the brain through evolution can never be observed. A more popular type of theory is cognitive development. Jean Piaget is considered the founder of this school of thought; after noticing that responses from children of different ages were qualitatively different, he identified several distinct stages of cognitive development and saw cognition as the primary facet of development, affecting the other areas more than vice versa (Newman 2007).

There are, of course, some serious ethical considerations when engaging in experiments with human beings, especially children who are not able to provide informed consent. Most scientific experiments require as many variables as possible to be controlled, so that a singular aspect of a phenomenon can be observed. This is usually ethically impossible when dealing with human beings, but case studies of extreme cases and carefully designed series of experiments that observe certain things from various angles can both help to overcome these issues. One interesting example of a finding brought out simply by many observations over an extended period of time is the development of a child's sense of self. There is evidence that toddlers become aware of themselves in a rudimentary physical sense, but awareness of their own interior thought process is a development of early childhood (Newman 2007; Papalia et al. 2004). This is related to the ability for abstract and symbolic thought, which also begins to develop during early childhood but is not fully formed until later (Newman 2007).