Childers decide by their emotions and if for their acts or words receive award or attention they try to repeat it and if for their words receive punishment they try to never repeat it .
and this really depend on their environment and family .
it is first step to find truth as a child.
As a child no one has the ability to validate what's true. Child believe all the stuff taught by parents and elders. On the basis of this a child try to figure out what is true what's not.
