Can you cry? For some, the volume of tears produced is shorthand for how emotionally capable an actor can be. New research sheds light on why this is far too simplistic a measuring stick. A New York Magazine feature describes how crying can be the direct result of the size of one's tear ducts. This is especially true when taking gender differences into account.
“There are several studies over the years that have shown that men have larger tear ducts in their eyes, so that it is less likely for the tears to well up to the point of spilling over the eyelid onto the cheek,” said Dr. Geoffrey Goodfellow, an associate professor at the Illinois College of Optometry in Chicago."
Hormones also play a factor. The more testosterone you have, the less likely you may be to cry. Of course, both testosterone and large tear duct size correlate with men, but obviously these differences in anatomy will vary within all men and women. So let go the expectation of liquid volume. As an acting teacher of mine was fond of saying when discussing if an emotional scene was effective: "It's not a matter of water."