Not long ago, Steven Pinker appeared on “The Colbert Report.” He managed to explain the functioning of the human brain to Stephen Colbert in only five words: “Brain cells fire in patterns.”

Pinker, Johnstone Family Professor of Psychology, appeared in Science Center B Tuesday evening (Oct. 23) to talk about his new book, “The Stuff of Thought.”

Fortunately, his audience there was able to take in more than five words at a time.

He was interviewed by Harvard College Professor Marc Hauser as part of the “Ideas on the Fringe” series of conversations, meant to highlight the work of faculty members “on the edge” of their discipline.

Their dialogue touched on a number of topics, including why human beings swear, the language of bribery, and how one memory can trigger another.

Pinker and Hauser began by talking about a challenge inherent in Pinker’s study of language as an entrée into the larger world of the study of human thought: At one level, language is the “crucial model system for thinking about the cognitive sciences,” as Pinker put it. Language is so essential to being human that studying language is an excellent approach to the study of human cognition.

But at another level, linguistics, as a discipline, has become so specialized, and so focused on structure at the expense of meaning, that it has become somewhat detached from usefulness to the cognitive sciences.

“I work hard to bridge those levels,” Pinker said.

Pinker takes issue with the “nativism” approach to linguistics, as espoused by Jerry Fodor of Rutgers University — what Pinker called “the carburetor theory of language.”

To express the concept at its most comically absurd — as Pinker is not reluctant to do — is to suggest that a child is born with an innate concept of, say, a carburetor or a trombone.

“The alleged fact” of this theory, Pinker said, “is that word meanings can’t be decomposed — they are cognitively atomic.”

Pinker counters that concepts like cutting or breaking can be deconstructed. There do, however, seem to be certain core concepts of the human mind — act, goal, time, place — that are reflected in human language and patterns of thought. The patterns these concepts form allow us to make connections between widely disparate phenomena. He told of complaining about a barber who failed to cut his hair sufficiently short and a restaurant that failed to cook a steak sufficiently well-done. At one level, the haircut and the steak are very different. At another level, the two both involve certain expectations not met. They share a certain “logical superstructure,” as Pinker put it. And thinking of one episode led him to think of the other. “This is a remarkable phenomenon in human memory retrieval.”

Pinker observed that he is often interested not so much in how something works but in “why does it work this way and not some other way?”

One of his interests is verbs, in all their glorious regularity and irregularity. Consider “make” as an irregular verb, for instance. Is there some sort of principle that determines that some verbs are “regular” (walk/walked) and some “irregular” — as in make/made, for instance?

Well, no. Pinker pointed out that the past tense of “make” was originally “maked.” But this form was mispronounced or misheard often enough that eventually “made” became the norm.

The phenomenon was “not rules and exceptions, but rules fed by ambiguous inputs,” as Pinker explained.

Pinker touched on a couple of specialized uses of language — swearing, and the language of offering a bribe.

“The taboo words refer to strong negative emotion” — whether in the realm of the theological, the sexual, or the scatological (“bodily effluvia”). And he also included the use of ethnic slurs — references to “despised groups” — in this class of highly emotive language.

“Cathartic swearing” — of someone who tries to slice a bagel and ends up slicing his thumb instead, for instance — he likened to the “yowl” of a trapped animal.

“The taboo words are tools with which you can ping someone’s amygdala,” the part of the brain concerned with motivation and aggression. “They’re an irresistible weapon for keeping people’s attention,” he said — to humiliate, or terrify.

On the other hand, he said, there is the phenomenon of casual swearing within a close circle of friends. In that context, the swearing is an expression of a kind of intimacy — a statement that “these are the friends with whom you can break these taboos.”

Another very specialized form of language is that of certain kinds of negotiations — such as the offering of a bribe. The one offering needs to make the offer clearly enough to be recognizable to the corrupt customs official (for example) who is open to it, but not so explicitly as to invite arrest by an honest official who would be offended by it.

The “Ideas on the Fringe” conversation series is part of Harvard’s Mind/Brain/Behavior Interfaculty Initiative. The next two sessions in the series will be Michael J. Sandel, the Anne T. and Robert M. Bass Professor of Government, talking about his book, “The Case Against Perfection: Ethics in the Age of Genetic Engineering,” on Nov. 6; and Edward O. Wilson, Pellegrino University Professor Emeritus, talking about his new book, “The Superorganism,” on Nov. 26.