[Raynor]

The problem with Elves is, since their hroa is made of the stuff of the Earth, and since Earth is Morgoth's Ring, they have a tendency to fall to Morgoth's will. (cf. in BoLT, the Spell of Bottomless Dread that is laid on all the Noldoli after their defeat at the battle of Unnumbered Tears, except in Gondolin). In fact, everything, if left to its own devices, will fall to Morgoth's Will, since he practically dominated the Music of the Ainur . . .

Now, consider Men. Their fëa ultimately belongs beyond Eä. So, they bring something from beyond it to the World. The fate of the World, to fall to Morgoth's will, is not their fate.

I side with davem on this issue; in Author's notes on Quendi and Eldar, HoME XI it is said that "no Elf of any kind ever sided with Morgoth of free will, though under torture or the stress of great fear, or deluded by lies, they might obey his commands", while in Of the begining of days, Silmarillion, it is said that

Yet the Elves believe that Men are often a grief to Manwe, who knows most of the mind of Iluvatar; for it seems to the Elves that Men resemble Melkor most of all the Ainur, although he has ever feared and hated them, even those that served him.

Moreover:

Originally Posted by Athrabeth Finrod ah Andreth

Whereas their own fear, being designed to remain in Arda to its end, imposed long endurance on their bodies; for they were (as a fact of experience) in far greater control of them.
...
His attempt to dominate the structure of Ea, and of Arda in particular, and alter the designs of Eru (which governed all the operations of the faithful Valar), had introduced evil, or a tendency to aberration from the design, into all the physical matter of Arda. It was for this reason, no doubt, that he had been totally successful with Men, but only partially so with Elves (who remained as a people 'unfallen'). His power was wielded over matter, and through it. But by nature the fear of Men were in much less strong control of their hroar than was the case with the Elves. Individual Elves might be seduced to a kind of minor 'Melkorism': desiring to be their own masters in Arda, and to have things their own way, leading in extreme cases to rebellion against the tutelage of the Valar; but not one had ever entered the service or allegiance of Melkor himself, nor ever denied the existence and absolute supremacy of Eru

It is apparent from these refferences that Men are more prone to corruption (esspecially due to their lesser control of fea).