The growth of intelligence

The growth of intelligence

No one doubts that intelligence develops as children grow older. Yet the concept of intelligence has
proved both quite difficult to define in unambiguous terms and unexpectedly controversial in some
respects. Although at one level, there seem to be almost as many definitions of intelligence as people
who have tried to define it, there is broad agreement on two key features. That is, intelligence involves
the capacity not only to learn from experience but also to adapt to one’s environment. However, we
cannot leave the concept there. Before turning to what is known about the development of intelligence,
it is necessary to consider whether we are considering the growth of one or many skills. That question
has been tackled in rather different ways by psychometricians and by developmentalism.
The former group has examined the issue by determining how children’s abilities on a wide range of
tasks correlate or go together. Statistical techniques have been used to find out whether the pa Hems
are best explained by one broad underlying capacity’, general intelligence, or by a set of multiple,
relatively separate, special skills in domains such as verbal and visuospatial ability’. While it cannot be
claimed that everyone agrees on what the results mean, most people now accept that for practical
purposes it is reasonable to suppose that both are involved. In brief, the evidence in favour of some kind
of general intellectual capacity is that people who are superior (or inferior) on one type of task tend also
to be superior (or inferior) on others. Moreover, general measures of intelligence tend to have
considerable powers to predict a person’s performance on a wide range of tasks requiring special skills.
Nevertheless, it is plain that it is not at all uncommon for individuals to be very’ good at some sorts of a
task and yet quite poor at some others. Furthermore, the influences that affect verbal skills are not quite
the same as those that affect other skills.
 This approach to investigating intelligence is based on the nature of the task involved but studies of
age-related changes show that this is not the only, or necessarily the most important, approach. For
instance, some decades ago, Horn and Cattell argued for differentiation between what they termed
‘fluid’ and ‘crystallized’ intelligence. Fluid abilities are best assessed by tests that require mental
manipulation of abstract symbols. Crystallized abilities, by contrast, reflect knowledge of the
environment in which we live and past experience of similar tasks; they may be assessed by tests of
comprehension and information. It scents that fluid abilities peak in early adult life, whereas crystallized
abilities increase up to advanced old age.
 Developmental studies also show that the interconnection between different skills varies with age.
Titus in the first year of a life interest in perceptual patterns is a major contributor to cognitive abilities,
whereas verbal abilities are more important later on. These findings seemed to suggest a substantial
lack of continuity between infancy and middle childhood. However, it is important to realize that the
apparent discontinuity will vary according to which of the cognitive skills were assessed in infancy. It has
been found that tests of coping with novelty do predict later intelligence. These findings reinforce the
view that voting children’s intellectual performance needs to be assessed from their interest in and
curiosity about the environment, and the extent to which this is applied to new situations, as well as by
standardized intelligence testing.
 These psychometric approaches have focused on children’s increase in cognitive skills as they grow
older. Piaget brought about a revolution in the approach to cognitive development through his
arguments (backed up by observations) that the focus should be on the thinking processes involved
rather than on levels of cognitive achievement. These ideas of Piaget gave rise to an immense body of
research and it would be true to say that subsequent thinking has been heavily dependent on his genius
in opening up new ways of thinking about cognitive development. Nevertheless, most of his concepts
have had to be so radically revised, or rejected, that his theory no longer provides an appropriate basis
for thinking about cognitive development. To appreciate why that is so, we need to focus on some
rather different elements of Piaget s theorizing.
The first element, which has stood the test of time, is his view that the child is an active agent of
learning and of the importance of this activity in cognitive development. Numerous studies have shown
how infants actively scan their environment; how they prefer patterned to non-patterned objects, how
they choose novel over familiar stimuli, and how they explore their environment as if to see how it
works. Children’s questions and comments vividly illustrate the ways in which they are constantly
constructing schemes of what they know and trying out their ideas of how to fit new knowledge into
those schemes or deciding that the schemes need modification. Moreover, a variety’ of studies have
shown that active experiences have a greater effect on learning than comparable passive experiences.
However, a second element concerns the notion that development proceeds through a series of
separate stages that have to be gone through step-by-step, in a set order, each of which is characterized
by a particular cognitive structure. That has thinned out to be a rather misleading way of thinking about
cognitive development, although it is not wholly wrong.