The traditional handshake plays a central role in our daily lives. We shake hands with people we know and those who are new to us. A handshake communicates our personality and mood to people and we use them as a mutually acceptable way of agreeing to seal the deal in endless scenarios.
But if you stop all that handshaking for a moment and take a closer look at the science behind this gesture, things might not seem quite so pleasant. This is in part because the human body contains many different types of bacteria. Some are good and we rely on these to help keep us healthy. Others are not so good and might make us sick.
We constantly gain and lose bacteria and so we are never sure when we might pick up an infection. Surfaces act as a route of transmission for bacteria and therefore every time we touch a surface we share bacteria unknowingly. This is why the risk of picking up an infectious disease is increased in places such as toilet seats. But have you ever thought about what bacteria you share when shaking somebody’s hand?
The power of a handshake
According to research from the University of Colorado, on average we carry 3,200 bacteria from 150 different species on our hands. And yet, shaking hands can be an everyday occurrence. It is considered to be an accepted means of greeting people and is the epitome of politeness in diverse cultures – especially in the Western world. As well as being a means of greeting people, it is also used to build rapport and trust with people. Ignoring a handshake is deemed to be impolite and rude.
Research has shown that on average, we will shake hands on average 15,000 times in our lifetime. So there are lots of opportunities for spreading bacteria between people – particularly if they are carrying potentially infectious bacteria that could make us ill. This includes faecal bacteria, which is quite common on hands.
This risk increases even further when we don’t wash our hands regularly – which is why good hand hygiene is essential. And of course, if the bacteria are resistant to antibiotics then we could inadvertently playing a role in spreading antibiotic resistance within our environment.
Fist pumps preferred
Some hospitals are so concerned about the spread of germs via handshakes that they are looking at creating handshake-free zones. Good hand hygiene and regular hand washing is often very low in hospitals. And hospital acquired infections are a major concern in healthcare institutions.
The hospital environment is regularly monitored for the presence of potentially infectious agents that can be acquired by a patient during a stay there. Critical care wards, and those containing vulnerable patients (such as the very young, elderly and immunocompromised) are especially important since patients are more prone to severe infections.
Research performed in neonatal intensive care wards – where sick newborn babies are cared for – explored the potential for handshake free zones. The wards ran a trial to see if they could discourage handshaking and actively encourage alternative greetings – such as fist bumps, smiling and eye contact – to try to reduce the person to person spread of infectious agents.
Alternative hand shakes
But it’s not just limited to fist pumps – around the world there are many different ways of saying hello and you don’t have to look far to find “healthier” ways of greeting. The New Zealand Maori, for example, rub noses and foreheads in their traditional hongi greeting and the Japanese bow to each other. Then there are the “dap greetings” such as high fives and fist bumps – which are commonly used by young people in the Western world.
Research has shown that the amount of bacteria transferred through a handshake is twice as much when compared to a high five. Significantly lower numbers of bacteria are also transferred when a fist bump is used. This is largely due to the difference in surface areas that are in contact with each other – despite the greeting taking the same time and number of bacteria on the surface of the person initiating the greeting on each occasion.
So, is the traditional handshake being replaced with more diverse and healthier options? This will take time – if it happens at all. But that said, as awareness of infectious diseases grows and people actively try to reduce the spread of infection, perhaps there could be a future where we all high five and fist pump rather than formally shake the hands of those we meet. Or at the very least better adoption of handwashing.