Educability-and-Group-Differences-1973-by-Arthur-Robert-Jensen

Language Deprivation 283
forces to encourage semantic development’. However, there is
another possible interpretation of these findings which brings
them theoretically under the purview of a much broader range of
findings in developmental psychology. First, there is a fundamental
biological principle, so general that it holds both across species
and within a given species, which states that the more prolonged
the infancy, the greater in general is the cognitive ability of the
species at maturity. Precocity of early motor development, as
assessed by infant tests, is negatively correlated with IQ at maturity
among whites; and low SES white children, who show higher than
average motor development scores in the first year of life, obtain
below-average IQs as teenagers (Bayley, 1966). At birth and during
the first year and a half of life, Negro infants, whether born in
Africa or America, are physically and motorically more advanced
than white infants; the majority of studies have shown this
(Ainsworth, 1963, 1967; Bayley, 1965; Curti et al., 1935; Durham
Education Improvement Program, 1966-7a, b; Falade, 1955,
1960; Geber, 1956, 1958a, b, 1960, 1962; Geber & Dean, 1957a, b,
1958, 1964, 1966; Gilliland, 1951; Kilbride, 1969; Knobloch &
Pasamanick, 1953, 1958; Liddicoat, 1969; Liddicoat & Koza,
1963; Masse, 1969; Moreigne & Senecal, 1962; Naylor &
Myrianthopoulos, 1967; Nelson & Dean, 1959; Pasamanick, 1949;
Ramarosaona, 1959; Scott, Ferguson, Jenkins & Cutler, 1955;
Vouilloux, 1959; Walters, 1967; Williams & Scott, 1953). Only
three studies, in African samples, have reported findings of no
significant differences in infant development (Langton, 1934-5;
Theunissen, 1948; Falmagne, 1959).2 Finally, language development
is a species specific characteristic peculiar but universal to
humans, which is intimately related to other developmental
processes, including motoric behavior. Precocity of language
development, as contrasted with the later role of language as a
vehicle for abstract, conceptual processes, thus may be viewed as
another reflection of generally accelerated sensori-motor development.
The generally negative correlation between rapidity of early
development and later level of cognitive ability reflected in intelligence
tests and other indices of conceptual ability is consistent
with the later deceleration of linguistically precocious children - a
deceleration that shows up at the age when the child’s language
begins to reflect more complex, abstract, and conceptual mental
processes.3