Etiquette for beginners

The Insider would like you to conduct a little experiment. It is preferable if you can do this in a crowded environment, say on your tube ride home or anywhere busy where you can catch the eye of a complete stranger while you are doing it.

Hold your hand out in front of you, palm upwards. Now fold your thumb and your pinkie finger in to your palm. Now fold your index finger and the finger adjacent to your pinkie finger in to join their fellows. You will be left with your middle digit proudly erect (I choose that word advisedly). Now raise your hand up to your face and use your remaining upright finger to rub up and down your nose, still with the palm towards you and with the digit perpendicular, as if you were pushing up a non-existent pair of spectacles. Obviously, if you actually do wear spectacles you will want to remove them first, if only because of what might happen next.

Now,