Over the last 3-4 decades, cognitive psychology has made a great deal of progress in understanding human thinking. Here I present a brief framework that covers the core discoveries made in this developing field.
In the framework are five basic functions of thinking: describe, elaborate, decide, plan, and act. These five functions organize into the Circle of Thought.
The circle begins with the world around us. Our senses collect information about our current situation that allows us to internally describe our surroundings -- a mental representation of where we are and what is happening around us. Vision enables us to determine where objects are located, and how to maneuver through space. Audition brings information about the remote and unseen, and to communicate with other creatures nearby. Smell and touch convey further details about our environment. Collectively, our senses gather extensive information about our surroundings so that our mind has an internal model of our situation. The world-within-mind is an imperfect copy of the real thing, but it is a remarkable and relatively accurate copy nevertheless.
The internal world description is expressed using several mental languages that are specialized for a particular kind of knowledge. One representation is used to describe space around us and allows us to navigate around obstacles. Another mental language is used for sequences such as a chain of events. We employ several mental languages because no one language seems to have the proper flexibility to easily express the various kinds of material our mind is concerned with. Still, we can oftentimes translate information from one mental language to another -- a hallmark of intelligence.
Our minds are not content to simply operate with the information given by our senses: often we can only see a parts of larger wholes, and it is important to understand the bigger picture. A short length of striped orange tail that appears behind a large tree or rock is probably not a disembodied object suspended in mid-air, but the only visible piece of an otherwise-hidden tiger. By elaborating upon what can be directly seen, we add a great deal of important information to our internal description of the world. Sherlock Holmes was especially good at elaboration, and you may wish to examine a charming example from The Red-Headed League.
Elaboration also complements sensory information by adding other kinds of knowledge to the world-within-mind. Emotions cannot be sensed directly (at least not by those who aren't psychic), but we can see the expressions on people's faces and listen to the quality of their voice for good clues about the emotional state of others. So, we make inferences about the emotions of others. Inferences are just another name for elaboration.
After developing a well-elaborated description of our surroundings, we are in a position to make decisions. Making decisions is actually a relatively simple process. Benjamin Franklin provided this charming description in a letter to his friend Joseph Priestly:
I cannot, for want of sufficient premises, advise you what to determine, but if you please I will tell you how. . . . My way is to divide a half a sheet of paper by a line into two columns; writing over the one Pro, and over the other Con. Then, during three or four days' consideration, I put down under the different heads short hints of the different motives, that at different times occur to me for or against the measure. When I have thus got them all together in one view, I endeavor to estimate the respective weights. . . . [to] find at length where the balance lies. . . . And, though the weight of reasons cannot be taken with the precision of algebraic quantities, yet, when each is thus considered, separately and comparatively, and the whole matter lies before me, I think I can judge better, and am less liable to make a rash step; and in fact I have found great advantage for this kind of equation, in what may be called moral or prudential algebra.
Having reached a decision, it would seem we would be ready for action. Yet acting right away may not be wise. Consider this story of Stupid and Stupider:
Stupid woke up one morning. "What a fine day it is!" he said to his roommate, Stupider.
"We should spend the day in the park!" his roommate replied. So the pair got into their car, and drove to the park.
After they had been in the park a few minutes, Stupid said, "I'm hungry!" To which Stupider replied, "Me, too! Why don't we get some sandwiches!"
The pair decided to return home to make sandwiches. Back at home, they looked for bread, but discovered they had none in the apartment. "Let's go to the store for a loaf," they decided.
They brought the loaf of bread to the clerk, who rang their purchase up, and said, "That will be one dollar."
"Please give the lady some money," Stupid said. "I don't have my wallet with me," Stupider replied. So, the pair drove back to their apartment to retrieve the necessary funds.
At the rate they are going, the fine day will be long past before Stupid and Stupider can collect all the supplies they need for their picnic at the park. By planning their actions in advance, the pair could have tremendously improved upon their efficiency. While at the house, they could have thought about what they would need at the park -- food, drinks, utensils, and a basket to carry everything in. Things they didn't have could have been picked up during a single visit to the store on the way to the park. By planning, we can recognize opportunities to reorganize our actions and minimize or eliminate costly, redundant steps (Sacerdoti, 1977). If Stupid and Stupider return to the park, then later drive back home for a knife to spread mayonnaise, make additional trips for something to drink, some potato salad, a fork to eat the salad with, and yet another to collect a blanket to cover the ground, to say nothing of trips for insect repellent, suntan lotion, and the like, they will be repeating a costly action (driving from the park to their apartment and back) multiple times -- an inefficient sequence of actions.
Planning also enables us to solve problems that, on the surface, have no obvious solution. Wolfgang Kohler, the famous Gestalt psychologist, was forced to stay on Tenerife Island during World War I. The island had a chimp colony, as well as a few farm animals like chickens and a dog. Kohler performed several experiments on these animals. One of the simplest was performed to test the ability of animals to exploit round-about routes. The experiment was conducted in a narrow area where a short chain-link fence ran between a large house and a small shed. Animals were tested by taking them down the alley between the two buildings up to the fence. The animals then observed some food being tossed over the fence onto the ground on the other side, in plain view, but out of immediate reach.
When chickens are tested with this problem, they run back and forth along the fence, seeking to find a way through it to the food. There is no visible path to the desired food, so the chickens dash madly back and forth, hoping to discover an opening. Dogs and chimpanzees act quite differently, however. The dog, upon seeing the situation, immediately spun 180 degrees around, ran back through the blind alley, around the shed, and over to the food. Chimpanzees were equally adept at solving this problem. (Kohler, 1925).Chickens apparently cannot plan to use a roundabout approach, and so are left helpless. Dogs and chimpanzees are able to plan in these situations, running directly away from the food to exploit a longer but unrestricted path to the goal. Planning this path depends centrally on memory: the indirect route cannot be seen by the animal, but must be inferred using the animal's past knowledge of its environs. That dogs have the capacity to remember local territory is not surprising when we consider that they once hunted over a wide range of territory, yet returned home nightly to a permanent den. Finding an efficient route home from wherever the day's hunt takes the pack has considerable survival value over re-tracing the path taken on each particular day. Chimpanzees are also territorial animals with a keen interest in local terrain. They remember the location of prime foraging areas, such as fruiting trees or active termite nests, from day to day and year to year (Goodall, 1986). All of these activities illustrate a vital role of memory in thought: memory permits us to 'go beyond' our immediate surroundings to consider possible avenues, tools, and methods that we might use to reach our goals. Without the ability to remember things that are not immediately present, planning would be impossible.
Planning conveys upon us two important advantages: it can greatly improve our efficiency and it also permits us to solve problems that have no self-evident solution. Successful planning requires memory to suggest resources (tools, implements) and routes that may be helpful in reaching our goals.
Finally the moment has come to act upon our plan. Here is where behavior arises -- Skinner's rats push their levers, Kohler's chimps run down blind alleys away from the food, and Stupid and Stupider return to their car to drive somewhere else. Oftentimes, our actions change the world in some way, if only to change our relationship with our immediate surroundings. When we are walking, our movement through the world exposes us to different terrain. If we open the refrigerator, we can now see what is inside that we might like to eat. At this point, the pathway of thought has come full circle, so we can begin a new cycle of describing the world, elaborating upon it, deciding what to do, planning our actions, and carrying them out.