Shaking hands probably started as a way to signal non-aggression. Putting out a hand and touching another person shows friendliness and lack of fear, along with lack of intent to harm the other person.

This social courtesy began about 2500 years ago in Greece, long before humans became aware of microscopic organisms that can spread disease.

Handshaking has faced competition in recent years from fist bumps and high fives exhibited by basketball players.

Hugs and cheek kisses have also served as handshaking alternatives, but not on the basketball court.

Donald Trump has long disliked shaking hands; he once called the behaviour barbaric. Trump describes himself as a germophobe. Not a bad trait to have during a pandemic.

In South-East Asia, most people never developed the Western habit of shaking hands.

They use other polite greetings, such as putting their hands together with palms touching in the Namaste gesture.

The current physical distancing guidelines bar shaking hands. The guidelines may stay in effect for months or years. That long pause in the behaviour will help break the habit.

Even if COVID-19 disappears, we will remain sensitised, as psychologists say, to the disease-spreading risk of shaking hands.

Greetings are an important part of social life. I shake the most hands when I play tennis with several others on Fridays.

After every set of tennis, we shake hands with our partner and with the opponents. As we usually change teams after each set, I often shake hands with seven or so people.

The playing has stopped now due to the virus, but in the weeks we played before stopping, we ceased shaking hands. Instead, we banged the bottom of our shoes.

I tried to introduce the delightful Japanese custom of bowing, but that was too foreign for my group.

So what will we all do in place of shaking hands? I enjoyed my visits to Japan enough that I may continue bowing or at least nodding.

With my tennis pals, I may continue with foot bangs or I may give a salute. For years I have been ending video chats with a salute. Maybe I am a natural soldier.

In the future, how will you greet others?

John Malouff is an Associate Professor at the School of Psychology, University of New England.