Not a game per se, but an activity. It makes you think, nonetheless. And hey, it's Monday, so doing this to half-asleep people will drive them crazy.

One at a time, ask a handful of co-workers,
friends, family members, or anyone else
handy to examine their own fingernails.
Pay attention to their responses.
What was difference in the male
response vs. the female response?

Click here for the answer.

Answer: Studies have revealed that women almost always hold their hands flat (palm outward) to check their own nails, while men almost always turn their palms up and curve their fingers inward, like a partial fist.