The test is actually pretty simple: draw an upper-case Q on your head.
Where did you put the tail of the Q? If it’s facing away from you for the benefit of someone facing you for example, you’re perceptive of how you’re seen by others, and therefore are naturally conducive to spinning tall tales.
If you drew it facing yourself, you’re more introverted and not a great fibber.
Watch the video and give it a crack!