A dear biologist friend once complained to me that the Basque verb hausnartu is used to mean both “to ruminate”, and “to ponder over”. He saw this as an example of very bad language behavior that should not be encouraged. I replied by noting that this can hardly be a whim of our native tongue, because many languages have metaphors relating thinking and chewing. For instance, in English, we can say I’ll chew on it meaning that I will think it over, and in Spanish it is common to use the verb rumiar “to ruminate” to mean the same thing.
So, is my biologist friend right, and we should stop mixing things up, or is he wrong, and this apparently crazy coincidence taps onto the deep makeup of our minds? Do thinking and chewing have something to do with each other? Well, I would not be writing this if they didn’t, would I?
In fact, recent research suggests a neurocognitive connection between thinking and chewing. Chewing has been found to maintain and enhance cognitive performance, though the precise nature of the effect is still not understood. The aspects of cognitive performance that benefit from chewing include memory, attention and executive function, and it does not make a difference whether one chews sugar-free or sugared gum, indicating that glucose is not the cause 1. When participants engaged in a series of tasks involving attentional networks they were significantly faster if they chewed before doing them, than when they completed the tasks without chewing before. The brains of the participants revealed that brain regions related to motor activity and attention were more activated in the chewing condition. These results indicate that chewing induces an increase in alertness in addition to an effect on motor control and, as a consequence, it improves cognitive performance 2
Back from chewing to language, then: it turns out that chewing on thoughts and ruminating on ideas are not arbitrary and whimsical mixtures of words. There is a good reason why children at school chew on the end of pencils, when there is a need to think harder. It is precisely what the Roman woman does in the alleged portrait of Sappho the famous Greek poetess that was found in Pompeii. There is no need to worry, no need to tell people not to chew on their thoughts; they have been doing it forever, as this ancient portrait shows.
On the contrary, this is just one example showing there is much more to metaphors than meets the eye. Indeed, one very active new direction in the study of human language and cognition involves the study of figurative meanings and metaphors, which are deeply rooted in our bodies. Psychologists, linguists and neuroscientists are increasingly persuaded that thoughts, feelings and behaviors are grounded in bodily interaction with the environment. In linguistics, embodied cognition has been argued to be at the foundation of metaphors, because their study reveals that they are not as arbitrary as it was once thought. For instance, across languages, words like happy, happiness are associated to up and upward motion, while words like sad, sadness are associated to down and downward motion. Some other metaphorical associations are language-specific, though, as when blue is associated to sadness in English, but not in Spanish 34. Many studies have shown that language comprehension activates embodied representations of the meaning of words. This means that when we hear or read a word like kicking, whose meaning involves moving a leg, the leg-area of our brains is activated, even though we do not move our leg 5.
These findings bring me back to Baruch Spinoza (1632-1677), one of the greatest rationalist thinkers, a philosophical scientist who is widely given credit for foreseeing the modern conception of the human mind 6. It is as if Spinoza had known about embodied cognition all along, when in Proposition 13 of Part II of the Ethics7, he wrote: The object of the idea constituting the human Mind is the Body.
Next time you find you are chewing on the end of a pencil when trying to solve a problem, or remember a word, do not chastise yourself: after all, it is your body at work, knowing that chewing helps thinking, when the thinking gets hard.
- Onyper S.V, Carr T.L. Farrar J.S. and Floyd B.R. (2011). Cognitive advantages of chewing gum. Now you see them, now you don’t. Appetite, 57, 2, 321-8 ↩
- Hirano Y, Obata T, Takahashi H, Tachibana A, Kuroiwa D, Takahashi T, Ikehira H, Onozuka M. (2013) Effects of chewing on cognitive processing speed. Brain Cogn. Apr;81(3):376-81. doi: 10.1016/j.bandc.2012.12.002 ↩
- Lakoff G. and Johnson, M. (1980) Metaphores we live by Chicago: University of Chicago Press ↩
- Lakoff G. and Johnson M. (1999) Philosophy in the Flesh, New York: Basic Books. ↩
- Pulvermüller, F.(2012). Meaning and the brain: the neurosemantics of referential, itneractive, and combinatorial knowledge. Journal of Neurolinguistics 25, 423-459 ↩
- Damasio, A., (2003). Looking for Spinoza: Joy, Sorrow, and the Feeling Brain, Harvest Books ↩
- Spinoza, B. The Ethics, Part III (New York, Dover Press 1955) ↩