Tuesday, December 30, 2008

Genes Implicated in 1918 Flu Pandemic

Unlike an individual and his or her own life, humanity does not have a "collective memory" which directly links the past, present and future. Older generations pass away, new generations are created, and some ideas, technologies, etc. are passed on to the next generation while others are ignored or forgotten about.

The fact that the persons who constitute humanity "today" is always (incrementally) changing is important to recognise. For it is easy for each contemporary generation to mistakenly think that the challenges they now face are novel since they themselves did not personally experience such a problem or dilemma before. To really capitalize on the adage "experience is the best teacher", we must become psychologically connected and continuous with the past (as well as present and future). This will help us avoid repeating the mistakes of the past, and better prepare us to meet the challenges of the future.

When one thinks of the year 1918 most of us will think of the end of the First World War. It is estimated that the "Great War" of 1914-1918 killed approximately 15 million people. World War I figures prominently in most history classes people take in school. And Remembrance Day helps keep the memory of the human cost of war alive in the minds of young and old alike.

But 1918 is also the year of another major event in human history. It is the year that humanity was plagued by a flu pandemic that infected a third of the world's population (approximately 500 million people) and killed 50 million people worldwide. Yet this event is not as prominent in our collective memory. Unlike the vivid images of WW1, the 1918 flu pandemic is less embedded in our collective memory (though you can find videos like this)

Why do we neglect something like the 1918 Pandemic when it killed more than 3 times the number of people killed in the four years of the "Great War"? Part of the answer is provided by the findings of psychology. The Availability Heuristic, for example, is a form of cognitive bias that skews our perception of risk. Risk is often influenced by the ease with which relevant instances come to mind. As there are plenty of images in our minds of war and violence (just watch the evening news any given night) we tend to think that violence is a (perhaps even the) major risk of death for humans. People often believe that violence is increasing (when in fact it is decreasing). Whereas risks like a flu pandemic do not typically concern people. Unlike suicide bombers and carjackers, we can't see viruses and thus, "out of sight, out of mind!".

The human brain has evolved to deal with what Richard Dawkins's calls "middle world". We have an intuitive understanding of the dangers associated with violence. We don't need to have a sound grasp of human biology or physics to know that guns and bombs can be dangerous. These things inhabit "middle world", and so we perceive them as real threats (which they are). But unfortunately we cannot so easily perceive the threats of ultramicroscopic infectious agents. They do not appear on episodes of "Cops" or on exciting amateur "You Tube" videos. Because these threats do not inhabit "middle world" this exacerbates the danger they pose to us. For it impairs our willingness to do what needs to be done to help prevent, and be prepared for, these threats.

One mystery of the 1918 flu pandemic concerned its ability to cause severe pneumonia in young, healthy adults. This study in the PNAS has identified a group of genes that helped make the 1918 flu so deadly. The Globe and CBC also have the scoop on this story.