Evolution

When you are living at the level of instinct, driven purely by evolutionary drives, your major concern in life is survival. And since reproduction is nothing but the survival drive for the species, it follows that when the survival drive is high, so is the reproduction drive. This is one of the reasons the poor  and impoverished, whose lives are dictated primarily by survival seem to have so many offspring. It is because the drive to survive and the drive to reproduce are aspects of the same evolutionary drive.

Our greatest blessing as human beings is that we have the ability or the free will to control the evolutionary drives and not be controlled by them. Or put simply, we can choose to reject the evolutionary drives. Self control is nothing but keeping the evolutionary drives in check. This allows us to plan for the future, and identify our self as something other than the purely physical. Self control also allows us the ability to step away from our drives and reflect on our true condition. This reflection soon develops into a feedback loop allowing further reflection and has been one of the major reasons for the success of the human race. In fact this ability has provided us with a most important skill in terms of long term planning, through delayed gratification.