By Norman Doidge, see the full article published by Tablet Magazine.
The somewhat paranoid ‘behavioral immune system’ you never knew you had, that may be making you miserable but is helping to keep you alive.
As horrifying as previous pandemics were—some, such as the plague of Justinian, estimated to have wiped out half the population of Europe, or the Spanish invasion of Mexico, estimated to have wiped out an even higher proportion of the Aztecs—we survived as a species. That the catastrophes were so dire also meant that the ongoing selection pressure of contagion became equally immense. This means that we have been “working” on this problem, in evolutionary terms, for a long time—long before modern science came along to help. Indeed, as the biologist J.B.S. Haldane posited 70 years ago, once we left the jungle and switched to agriculture, it is quite likely that adapting to infectious disease became the main driver of natural selection, replacing attacks by large animal predators.
Thus “we,” and “our bodies,” learned a thing or two about contagion, including that no two epidemics are identical. This meant our cellular immune systems had to become “intelligent” in a rudimentary way, and stay “well-informed,” and capable of “recognizing” new invaders and “remembering” them.
But it is not just our immune system that protects us.