Development of behaviors

Abstract

Behavior requires functional muscles, but the development of behavior depends primarily on events within the nervous system. The pattern of development is similar in invertebrates and vertebrates. When nerve cells first appear, they are not yet connected with other cells, and hence they cannot produce behavior. However, once neurons start to form synapses, behaviors begin, although at first they may be simple. As the nervous system matures, several factors – including hormones, activity within the neurons, and input from the environment – modify the system and consequently the behavior produced, allowing it to become a more effective response to ongoing events.