In grammar school, they told us that thought was the sixth sense. But you hear all kinds of crazy things in grammar school. The picnic benches had bolts that, should their paint chip off, would release kooties, but I live to tell you about it.

Thinking is largely about processing existing sensory data, so I suppose that’s why you don’t hear that it’s the sixth sense. Intuition is a candidate for “sensiness,” because of the roundabout way that most people become conscious of intuition, but it’s still a form of thought. Well, unless you believe that your intuition is psychic. Now that would be sensing transpersonal or otherwise cosmic information with a yet undiscovered sense organ. Hold that thought.

Then there’s your vomeronasal organ. It senses pheromones, and alters your behavior, hormones, and who knows what else. With alcohol, it causes paternity suits. With lower mammals, it causes paternity without lawyers.

But there’s a new kid on the block, and a recent research study by Goehler and colleagues on it is quite telling. I’m talking about the immune system. There is increasing evidence that your immune system communicates through the vagus nerve, and probably the blood system as well through neurotransmitters and cytokines. This study, however, focuses on the behavior of mice who have a gastrointestinal bacterial infection.

When the immune system detects an infection in the gut, it increases the anxiety of mice. From the perspective of evolutionary psychology, the researchers are guessing that this anxiety may improve the odds of survival. By staying away from scary places, like open spaces where predators will see a rodent, the rodent is less likely to need to escape. If being sick will slow his reflexes and other survival abilities, then it’s a good idea to be sidelined. This may extend to other sick feelings and behavior, such as fatigue.

Given its evolutionary value, this power of the immune system may apply to other mammals, like us humans. Will we discover that this evolutionary factor is causing some people to be anxiety-prone? Will detox diets be found to improve some people’s anxiety? Are there other ways the immune system is implicated in anxiety or other emotional problems?

And then there is the matter of this immune system/nervous system communication being a two way street. That’s a big reason why there’s such an interest in the effect of the mind on health (as in neuroimmunology).

No one’s ever told me this was a cure for anxiety, but if you’re feeling stuffy and tired, and don’t need to hide out to avoid predators, I recommend menudo. It’s an old hangover cure, it brings comfort to cold sufferers, and now, it’s for your sixth sense.

Reference

Goehler, L. E., Lyte, M., & Gaykema, R. P. A. (2007) Infection-induced viscerosensory signals from the gut enhance anxiety: implications for psychoneuroimmunology. Brain, Behavior, and Immunity. Elsevier. Aug; 21(6): 721-726.