mathematical and scientific operations; and modify
their comments to reflect the perspective of the listen-
er.
Beginning in adolescence and continuing
throughout the adult years, formal operational adults
are potentially able to apply logic to all situations—
hypothetical or real. Piaget saw this ability to have
‘‘thought take flight’’ as a partial explanation for the
expansiveness of adolescent behavior and even for
the difficulty adolescents and young adults have in
initially settling into productive adults lives.
The Contextualist Worldview
Although there are many differences between a
mechanistic and an organismic worldview, they nev-
ertheless share one important characteristic—they
each view the process of development as universal.
This emphasis on universality is one of the ways in
which these two worldviews can be contrasted to the
third, Contextualism. Contextualists do not believe
that there are universal laws of development; rather,
they argue that the forces that contribute to develop-
ment are specific to historical time and social place.
Contextualists make their nonuniversal argu-
ment for two reasons: one empirical and one concep-
tual. From an empirical perspective, they argue that
there is more than enough variability in the data com-
paring individuals and groups from different settings
to raise serious questions about the assumption that
human development reflects the same universal set of
variables. From a conceptual perspective, contextual-
ists argue that since it is impossible to ever have an ob-
jective (i.e., context-free) perspective on human
development, then it is impossible to make judg-
ments that are not culturally based.
Lev Vygotsky’s (1896–1934) cultural-historical
theory of human development is a good example of
a theory rooted in a Contextualist Worldview since it
places great emphasis on the role of culture in both
defining and then transmitting the sign and symbol
systems used in that culture. Sign and symbol systems
are the ways cultures note and code information.
They are reflected in the nature of the language, in
ways for quantifying information, in the expression of
the arts, and more generally in the ways people estab-
lish, maintain, and transmit social institutions and re-
lationships across generations.
Vygotsky saw language as the defining character-
istic of humans as a species, the one element that dis-
tinguishes humans from other species. Language
allows for a shared communication, which in turn al-
lows for collective effort or labor. This effort, in turn,
sets the foundation for the progressive evolution of
culture across generations. To Vygotsky, culture is a
uniquely human phenomenon, allowing history to re-
place biology as the defining element in the lives of
humans.
Of the various elements of Vygotsky’s theory, the
one that continues to receive the most attention, is his
concept of the zone of proximal development (ZPD).
Vygotsky saw the ZPD as the mechanism through
which a culture’s sign and symbol systems were passed
from generation to generation; not surprisingly,
many educators see it as the key element in the educa-
tional process of children. The ZPD represents an in-
terval between what a child (or adult) is able to do
alone and what that person can do with the support
of a more skilled person. For activity in the ZPD to be
educationally meaningful, the teacher must have a
clear sense of both what the child should learn and
the child’s current interests and abilities. In essence,
intersubjectivity needs to be established between
teacher and child so that the learner understands the
goals of the teacher, and the teacher understands the
child’s present level. A failure to establish intersubjec-
tivity indicates that the teacher will be ineffective in
helping the child acquire new information because
the strategies the teacher uses to help support the
child’s learning will be ineffective or inappropriate.
In addition to highlighting the educational pro-
cess, the ZPD also highlights another important ele-
ment of Vygotsky’s theory, namely, the notion that
the intermental always precedes the intramental. By
this Vygotsky meant that all knowledge is first ac-
quired as social knowledge and only later is it inter-
nalized and comprehended by the child. It is because
all knowledge is first transmitted as social knowledge
that the cultural-historical context of a particular cul-
ture is so important in understanding and defining an
individual’s development.
People sometimes tend to think of theories as ab-
stract and not useful, as something only academics
argue or care about. Actually nothing could be further
from the truth. Theory is the foundation upon which
all everyday ideas about human behavior and devel-
opment are based. In the words of psychologist Kurt
Lewin (1890–1947), ‘‘there is nothing so useful as a
good theory.’’See also: DEVELOPMENTAL NORMS; ERIKSON, ERIK;
FREUD, SIGMUND; MILESTONES OF
DEVELOPMENT; PIAGET, JEAN; SKINNER, B.F.;
VYGOTSKY, LEVBibliography
Bandura, Albert. ‘‘Human Agency in Social Cognitive Theory.’’
American Psychologist 44 (1989):1175–1184.
Bandura, Albert, and S. A. Ross. ‘‘Transmission of Aggression
through Imitation of Aggressive Models.’’ Journal of Abnormal
and Social Psychology 63 (1961):575–582.416 THEORIES OF DEVELOPMENT