Historian Ian Morris noted there was trade in goods and inventions between the empires of the West (Britain and then the United States) and those of the East (particularly in China). Inventions such as paper, noodles, gunpowder as well as luxuries like silk and ceramics. And also travelling along the trade routes were germs.
The Black Death originated in China in the mid 1300s, travelled to the Mediterranean and north Africa and then on to southern England in 1348, northern Britain and Scandinavia by 1350.
• Coronavirus: Everything you need to know
• Coronavirus victim attended Tool rock concert - health officials' advice for fans
• Coronavirus latest updates and essential information
• Coronavirus: New Zealand alert over cruise ships
In evolutionary terms, those who avoided strangers who seemed ill would have been more likely to survive this and other contagions. We would expect that the signal of "foreign, plus illness" would have reinforced in-group attraction (given that we are likely to have antibodies to local diseases) as well as rejection of outsiders.
It is probably no coincidence that out-group members are likely to be compared to animals associated with disease – such as cockroaches, maggots and rats.
Recent research indicates that such a contagion signal does heighten what social psychologists term authoritarian inclinations – resulting in greater emphasis on who's in and who's out.
Damian Murray and colleagues found that in countries with a higher burden of parasitical diseases (including TB, malaria and dengue) individuals were more likely to express authoritarian attitudes (including punishment of those not following traditional norms), and in turn were more likely to have authoritarian governments (with less tolerance of political rights and civil liberties). They suggest that conforming to mandated practices could have helped control the spread of disease, so setting up the conditions for the transmission of ritual behaviours.
In this context, it is not surprising that as people hear more about the risk of coronavirus there has been a surge in xenophobic responses towards people who don't conform to some people's view of what a Kiwi looks like.
Meanwhile, in New Zealand (and in the US) we have politicians in campaign mode. This is too good to be true for politicians who are targeting the authoritarian psychographic. As the threat heightens with increasing infection, we can expect to see more people tip into that zone. And more xenophobic responses – from the public and opportunistic politicians.
Shane Jones is staking his claim for that fearful group (and putting up his hand to take over NZ First) by targeting Indian students.
Expect to see President Trump (a renowned germ phobic) blame foreigners for polluting the once-great United States.
We can't blame people for feeling fearful. Nor for responding to inbuilt tendencies towards disgust and rejection of outsiders when primed by fears of contagion. Of course, many politicians do whatever works.
How can we instead develop positive alternatives? Particularly in humanising those who have the bug, or could be seen as vectors of disease?
When the Wuhan evacuees arrived in Auckland they were greeted with "Welcome Home" posters. We could also celebrate those who are helping – the health professionals, the drivers and pilots who transported these people.
More publicity about how countries are sharing knowledge of what works – so that we learn that they are people doing their best, learning in the process, and in turn helping us with our preparations and responses.
Potentially, we could reach out by sending our own public health and medical specialists into vulnerable areas – such as the Pacific islands. Signaling that we are caring and keen to share our expertise to help these people.
In turn we can help others by our own hygienic practices and showing our care for work colleagues or neighbours who are quarantined or are self-isolating – in a germ-free way of course.
• Stewart Forsyth is an organisational psychologist and executive coach.