The traditional explanation of delayed maturation age, as part of an
evolved life history, focuses on the increased costs of juvenile mortality
due to early maturation. Prior quantitative models of these trade-offs,
however, have addressed only morphological phenotypic traits, such as body
size. We argue that the development of behavioral  skills prior to
reproductive maturity also constitutes an advantage of delayed maturation
and thus should be included among the factors determining the trade-off for
optimal age at maturity. Empirical support for this hypothesis from animal
field studies is abundant. This paper provides further evidence drawn from
simulation experiments. "Latent Energy Environments" (LEE) are a class of
tightly controlled environments in which learning organisms are modeled by
neural networks and evolved according to a type of genetic algorithm. An
advantage of this artificial world is that it becomes possible to discount
all non-behavioral costs of early maturity in order to focus on exclusively
behavioral consequences. In spite of large selective costs imposed on
parental fitness due to prolonged immaturity, the optimal age at maturity
is shown to be significantly delayed when offspring are allowed to learn
from their parents' behavior via imitation.