Nido Qubein is a name I am familiar with because of the National Speakers Association. He is a polished and renowned speaker and business consultant, winning some of the highest awards in public speaking. He writes on Ten Points on Human Motivation - including:
Motivation is universal.
Everyone has an internal wellspring of potential motivation. For some all you have to do is open the tap with an opportunity and it gushes out. Others can only channel their internal motivation in certain directions. Management’s challenge is to find those channels.
Read the rest of the points here