Not all psychologists are primarily interested in early
development. But even researchers (22)---- to
understand complex adult behaviours often find it useful
to examine those behaviours during periods when they
are not so complex. For example, humans are capable
of sophisticated communication (23)---- the fact that our
languages follow systems of rules. But determining what
these rules are has proved very difficult (24)----
researchers. One approach to this problem is to study
our language system (25)---- it is being acquired. So, in
language development, as well as in many other areas,
the growing child is a showcase of developing skills and
abilities, and researchers interested in different aspects
of human development have (26)---- this fact to help
them understand adult behaviour