The Judeo-Christian story of the Garden of Eden tells us that the devil, disguised as a snake, tricks Adam and Eve into eating of the forbidden fruit on the Tree of Knowledge of Good and Evil. However, a recent study suggests that early, long-term exposure to snakes may have actually influenced the evolution of the human brain. Perhaps it’s not just a story, after all.

Brain as a survival machine

Like all other life on this planet, humans evolved in order to survive, and our brains have become spectacular survival machines. By understanding the threats our earliest ancestors faced in our early history, we can understand why our brains function the way they do today.

For example, one theory suggests that the volatile ecosystem experienced by the earliest humans encouraged the development of adaptability to change. This ability came in handy when other species were dying out in the face of drastically changing climates, shifting tectonic plates, and other cataclysmic changes in the early days of life on earth.

One famous group of animals that failed to adapt, the dinosaurs, gave way to the small mammals that eventually gave birth to the primate line. But these small mammals had a fierce predator they had to face if they were going to survive and evolve into primates: the snake.

The snake response

Most of us will admit to having a fear of snakes, and we might also be a bit embarrassed—calling our feelings “irrational.” However, research is building a compelling case that our brains are actually hard-wired to fear snakes, and that this trait came in handy when early primates were fighting for survival.

Anthropologist Lynne Isabel suspected that early mammals escaped being squeezed or poisoned to death by selecting for superior vision, enabling them to pick out a lurking snake. What makes her work especially interesting is that Dr. Isabel worked with neuroscientists to test her theory. The resulting study demonstrated that a group of macaque monkeys with no previous exposure to snakes reacted more strongly to snakes than to other stimuli.

This reaction has been attributed to evolutionary “hard wiring” that may have ensured the survival of early primates.

What’s your snake response?

This news makes me ask two questions:

  • What other snake responses have made us who we are? What other hard-wiring are we going to discover deep inside our brains in the years to come? Do we have a survival instinct for appreciating beauty, loving family members, or believing in ourselves? As we come to know more about how each individual brain is wired, might there also be conclusions that can be drawn about organizations and societies? For example, will a work group that narrowly avoided multiple efforts to re-engineer it out of existence develop a group instinct for surviving down-sizing initiatives?
  • What else did the Book of Genesis get right? Maybe it’s time we start reading it as natural history, rather than as a spiritual allegory.