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Deena R. Palenchar
THEORIES OF DEVELOPMENT
Why are humans the way they are? Why is it that the
abilities of children seem so different than those of
adults? What can one do to help children become
fully developed adults? These are the kinds of ques-
tions that theorists of human development try to an-
swer.
As it is easy to imagine from questions that are so
broad, the answers theorists offer are equally broad,
typically telling more about people in general than
about what any one person is likely to do on a particu-
lar day. Furthermore, given such questions, the an-
swers theorists arrive at are not always the same. In
some cases this is because different theorists study dif-
ferent aspects of human development; in other cases
it is because different theorists do their work using
different sets of assumptions.
These differing assumptions reflect theoretical
debates about four things. First, they reflect a debate
about what in fact one should look at in order to mea-
sure the course of human development—should it be
someone’s actual behavior or the presumed internal
psychological processes that might be reflected in be-
havior? Second, theorists debate how best to portray
humans—are humans autonomous, self-directed in-
dividuals or ones acting largely in response to exter-
nal events? Third, theorists differ as to the
generalizability of their findings—is there one theory
that explains the development of all people in all
places at all times or are there many theories, each
specific to a historical time and place? Finally, theo-
rists differ as to the actual methods that should be
used to divine the answers to all of these questions.
One useful way to understand these different ap-
proaches to the study of human development is to
think of them as reflecting relatively distinct world-
views. A worldview is not a theory but something larg-
er. It represents a set of assumptions that a theory
may draw upon to serve as the foundation of that the-
ory’s investigations. Three worldviews are evident in
the work of developmental theorists. They are re-
ferred to as the Mechanistic Worldview, the Organis-
mic Worldview, and the Contextualist Worldview.
Theories that share the same worldview, even if they
are not studying the exact same thing, are neverthe-
less said to belong to the same family of theories.The Mechanistic Worldview
Theories built on a Mechanistic Worldview reflect
a belief that behavior and behavior change are pre-
dictable, lawful phenomena that can, theoretically at
least, be fully understood through the use of systemat-
ic, objective empirical research methods (empirical
meaning that the methods rely on observation or ex-
perimentation). Secondly, mechanists believe that be-
havior is caused by either factors external to the
individual (efficient causes) or those defining the in-
dividual’s biological makeup (material causes). Effi-
cient causes include such things as parenting style,
educational opportunities, and peer group composi-
tion. Material causes include inherited genetic char-
acteristics and more general biological qualities such
as temperament or information processing capability.
Two prominent examples of work within a Mech-
anistic Worldview are the operant conditioning
model, most closely associated with B. F. Skinner
(1904–1990), and the behavior genetic model, associ-
ated with the work of Robert Plomin and Sandra
Scarr, among others. These two models are very con-
tradictory. Skinner’s work reflects the nurture side of
the nature-nurture debate, while Plomin and Scarr’s
work reflects the nature side of the debate.Operant Conditioning Model
Skinner’s operant conditioning model examines
the relationship between a behavior and its conse-
quence. As a model of human development, the oper-
ant model is seen as a means of understanding how
life experiences influence an individual’s actions. It
demonstrates how changes in the consequences of
one’s behavior can in turn modify that behavior. In
essence, responses are more likely to increase if fol-
lowed by a positive (i.e., desirable) consequence and
less likely if followed by a negative (i.e., undesirable)
consequence. Skinner also found that the timing or
schedule of the contingent reinforcement is an equal-
ly significant variable. Continuous reinforcement is
generally seen as more effective in establishing a re-
sponse; variable or intermittent reinforcement is seen
as more effective at maintaining a response at a high
level once it has been established.
Skinner restricted his actual work to laboratory
animals—pigeons and mice in particular—but he
made it clear in his writings that he saw these general
principles as governing the behavior of all species,
human or otherwise. Further, others working in this
tradition have demonstrated that these principles of
operant conditioning are very useful in helping to un-
tangle complicated family dynamics as well as the
more subtle forms of observational learning.THEORIES OF DEVELOPMENT 413