The strange emotional power of swearing—as well as the presence of linguistic taboos in all cultures— suggests that taboo words tap into deep and ancient parts of the brain. In general, words have not just a denotation but a connotation: an emotional coloring distinct from what the word literally refers to, as in principled versus stubborn and slender versus scrawny. The difference between a taboo word and its genteel synonyms, such as sh*t and feces, c*nt and vagina, or f*cking and making love, is an extreme example of the distinction. Curses provoke a different response than their synonyms in part because connotations and denotations are stored in different parts of the brain.
The mammalian brain contains, among other things, the limbic system, an ancient network that regulates motivation and emotion, and the neocortex, the crinkled surface of the brain that ballooned in human evolution and which is the seat of perception, knowledge, reason, and planning. The two systems are interconnected and work together, but it seems likely that words' denotations are concentrated in the neocortex, especially in the left hemisphere, whereas their connotations are spread across connections between the neocortex and the limbic system, especially in the right hemisphere.
A likely suspect within the limbic system is the amygdala, an almond-shaped organ buried at the front of the temporal lobe of the brain (one on each side) that helps invest memories with emotion. A monkey whose amygdalas have been removed can learn to recognize a new shape, like a striped triangle, but has trouble learning that the shape foreshadows an unpleasant event like an electric shock. In humans, the amygdala "lights up"—it shows greater metabolic activity in brain scans—when the person sees an angry face or an unpleasant word, especially a taboo word.
The response is not only emotional but involuntary. It's not just that we don't have earlids to shut out unwanted sounds. Once a word is seen or heard, we are incapable of treating it as a squiggle or noise; we reflexively look it up in memory and respond to its meaning, including its connotation.
Much more in this long but interesting article by Steven Pinker |