...and, let's not forget Willpower!

Maybe motivation is just a byproduct of hormones? 

Our bodies create hormones and those hormones influence us. There’s cause and effect in action which is consistent with motivation and, perhaps, there's an argument this hormone-induced motivation is the only motivation. I mean, without our hormones we wouldn't be doing anything and with our hormones we do the things we do. And as hormones ebb and flow people do different things and act in different ways...which is consistent with experiencing a range of motivations. So, without hormones we would have no motivation.

And, there's scientific evidence 'proving' that hormones serve certain roles and different hormones trigger/motivate different thoughts and behaviour. 

No question – hormones play a role in motivation.

And, that raises some questions –

Are hormones the sole cause of motivation?

Are hormones the root-source of motivation?

How does DNA fit in?

Are motivations simply genetic [destined/predestined] legacies?

Are self-help books a complete waste of time and money?

or...

Does willpower provide each of us the opportunity to decide and influence our motivations?