Before the late 1800s, habits like sharing cups with strangers and spitting in public even amidst crowds weren’t considered unsanitary. Then a tuberculosis outbreak came, and our behavior changed — in some ways irrevocably and in some ways temporarily.
This is a new social norm that has already been built up since the SARS outbreak in which the face mask was constructed
as a sign of civic responsibility.
I still compulsively wash my hands, 17 years after the outbreak. I have friends that have been using toothpicks to press elevator buttons for years. Some use tissues to open the doors of public washrooms, or carry spare masks in their handbags in case they catch the sniffles. This is all evidence of the indelible impact SARS has had on Hong Kong’s psyche.
That’s what happened after 9/11 completely transformed the way people fly. First people accepted that knives were no longer allowed on flights, then as new threats emerged, travelers agreed to take off their shoes during security screenings and tolerated the ban on water bottles.