Both Piaget and Vygotsky stressed the role of mediation in human devel
opment. While Piaget, within his cognitive adaptational model of devel
opmental constructivism, identified mental mediation as the primary me
chanism underlying intellectual development, Vygotsky emphasized the c
ultural mediation by tools, signs, and social interaction as the core
mechanism of higher mental functioning. Despite important differences
between these two theorists' conceptualizations of developmental media
tion, they shared the view that cognitive structures are built through
a process of internalization by reconstituting external (inter)action
s in a new form on an internal plane. Neither Piaget nor Vygotsky, how
ever, paid adequate attention to what Simmel has called the cultivatio
n principle. According to this principle, the cultivated mind is const
ructed through the ongoing transactions of the person with his or her
cultural environment, i.e., permanently changing cultural forms, such
as personal possessions, places, settings, institutions. These cultura
l forms are mostly overlooked in contemporary developmental theorizing
and research. Simmel's cultural forms result from externalizations of
former person-culture transactions. In other words, a person shapes o
r creates his or her own developmental conditions by a process of tran
sactional constitution between himself or herself and his or her cultu
rally structured environment. Thus, human development is not as indivi
dual biased as, for example, the Piagetian model of adaptive construct
ivism assumes. Instead, based on a cultural-mediational model developm
ent is structured through person-culture transactions as they are crea
ted and recreated by cultivating one's own culture (external mind) tow
ard cultivating one's own mind (internal mind). These transactions can
be facilitated, to varying degrees, by social coconstructions. Simply
put, the internal and the external mind (culture) mutually cultivate
or co-develop each other. (C) 1998 Academic Press.