Zombie Spiders, The Emotion of Disgust, & Parasite Stress: My Thoughts on This is Your Brain on Parasites

in what is a trend in my list of books I read, I just completed another which deals with the host-parasite interaction from the angle of how parasites influence behavior: This is Your Brain on Parasites: How Tiny Creatures Manipulate Behavior and Shape Society by Kathleen McAuliffe. 

The aim of this extraordinary book is to explore the many ways in which parasites, with a view to their own reproductive success, change behavior in the species they infect. This ranges from very subtle perturbations to seismic shifts. McAuliffe expertly provides multiple examples from varied species including zombified spiders to sexually-charged rabid dogs to insights into human psychiatric disease. Her discussion of the emotion of disgust and its potential origin and usefulness when it comes to parasitical infection is enlightening as is her discussion of the origins of vampire myths.

Another fascinating aspect of this book is its probing of the characteristics of high parasite-burden human societies. While causation is difficult to establish -- nor maybe even valid in such a context -- the correlations produced are extremely interesting. The "parasite stress" a country, community, a village, a people, or region faces has a high correlation to their view of immigrants, their views on gender issues, and a tendency to dictatorial-style governments. This last is an extremely important finding and something I think deserves further exploration. Parasite stress, the way I conceptualize it, not only may have subtle direct behavioral consequences but also will tend to create a poverty trap for the infected, stifling opportunities for economic activities necessary for flourishing and ripening the prospects for dictatorship to rise in an environment in which challenges are not feasible as people stick to their clans and deal with the onslaught of infectious disease.

The lines of inquiry in this book are very intellectually stimulating and do not undermine human volition. Human free will is axiomatic however alterations in cognition can occur for a variety of reasons, some of which may be parasitic in origin. For example, the prevalence of toxoplasmosis in certain psychiatric conditions cannot, based on its pathophysiologic characteristics, be purely coincidental.

The book is highly recommended.