Probability Interpretation of QM

[Bobhawke]

What is it that motivated Max Born to interpret psi in Schrodinger's equation as a probability amplitude? It seems a very strange thing to do - first of all what made him think that the elementary properties of particles should be of a statistical nature, and second why did he interpret it as a probability amplitude rather than just a probability?

[malawi_glenn]

probability must be a real, positive value. The wavefunction can obtain both negative and complex values-> hence the need to interprent it as an amplitude

[ThomasT]

What is it that motivated Max Born to interpret psi in Schrodinger's equation as a probability amplitude? It seems a very strange thing to do - first of all what made him think that the elementary properties of particles should be of a statistical nature, and second why did he interpret it as a probability amplitude rather than just a probability?
I was curious about this myself and so asked basically the same question in this thread:

http://www.physicsforums.com/showthread.php?t=244206&highlight=ThomasT