For Skinner, private events are natural and like public events in all important respects. Even if thoughts are natural events and may be said sometimes to affect behavior, still they never cause behavior in the sense of originating it. Although the origins of behavior lie in the present and past environment, private events figure importantly in Skinner's analysis of certain types of behavior, particularly self-reports, which we will consider now and in chapter 6, and problem solving, which we will take up in chapter 8.
Since private events belong to the person, rather than to the environment, they are best understood as behavioral events. Broadly speaking, there are two kinds: thinking events and sensing events.
Thinking, for the present discussion, is speaking privately, what Watson called “sub-vocal speech.” This may seem too narrow, because thinking is used in many other ways in everyday talk. “I am thinking of going to a movie” means I am inclined, or likely, to go to a movie. “I am thinking of a painting I once saw” means I am imagining the painting, and is best understood as a sensing event. “I think capital punishment should be abolished” puts thinking in the same position as believing, which means I am likely to argue against capital punishment and engage in other activities like that.
Thinking as sub-vocal speech is usefully set apart from sensing events, because thoughts have a relationship to public speech that sensing events do not. A thought may be stated publicly or privately (Skinner used the words overt and covert). I may say to myself aloud, I wonder what will happen if I push this button, or I may whisper it to myself, or I may say it sub-vocally. These events are all much the same; the first two might be overheard, whereas the third cannot be. Sensing events, however, have no such public counterparts. The public parts of smelling a skunk (holding one's nose and talking about the smell) differ in form from whatever private sensing might be involved.
Sensing events are best understood in contrast with the usual view of sensation and perception, which Skinner calls “copy theory" Some ancient Greek philosophers, puzzling as to how it is possible to see objects at a distance, theorized that the objects must send copies of themselves to our eyes. If I see a tree across the road from me, it must be because the tree sends little copies of itself to my eyes. The modern view is similar, except now we say that the tree reflects light, which passes through the pupils of my eyes to form images on the membranes at the rear of my eyeballs. These images substitute for the Greek copies.
This notion may be useful in understanding some things about the eyes, but it in no way explains seeing. The problem of how the tree is seen is now replaced by the problem of how the tree's copy is seen. Copy theory has all the defects of mentalism. The appearance of an explanation—you see the tree because you have a copy of it in your eye or in your brain—distracts us from our attempt to understand what seeing is. The copy is superfluous, because the question remains the same whether we ask about seeing the tree or seeing the copy: What is it to see something? In particular, copy theory fails to explain why seeing is selective. Not all objects that reflect light to our eyes are seen. Why do I see the tree and not the road? How is it possible for one person to point something out to another, to “get” you to see something? How is it possible for someone to look right at a sign and yet not see it?
To the radical behaviorist, sensing and perceiving are behavioral events, activities. The thing that is seen, heard, smelled, felt, or tasted is a quality of the event—that is, part of the definition of the event. Seeing a wolf is qualitatively different from seeing a bear. The two events have much in common—both are episodes of seeing, rather than hearing or walking—but they also differ. They are different activities, just as walking to the store differs from walking to the bank. The goal or object of walking (store or bank) is part of the definition of the activity. If I say, It’s a nice day on one occasion and, There’s a tiger behind you on another, both are episodes of speaking, but the two actions differ in the same way as the two actions of walking; the nice day and the tiger are part of the definition of the action. Just as one cannot walk without walking somewhere and talk without saying something, one cannot see without seeing something. The some- wheres and the somethings differentiate among different acts of walking, talking, and seeing, but not as attachments to them. They are different actions, not the same action applied to different things.
That the goal or object of a sensing event is a quality of the event can be seen more clearly when we talk about senses other than vision. In such talk we rarely fall prey to copy theory. If I hear a violin playing, someone would rarely assert that my activity of hearing somehow fastens onto the sound of the violin. The sound is part of the activity, the result of the activity, perhaps. Hearing a violin and hearing an oboe are different activities, not the same activity applied to different sounds. An ancient Zen Buddhist puzzle goes, “If a tree falls in the forest, and no one is there to hear it, does it make a sound?” The behaviorist's answer is “no,” because a sound exists only as part of an action of hearing. In the same way that hearing a violin differs from hearing an oboe, so seeing a bear differs from seeing a wolf.
The relationship between seeing and the thing seen becomes clearer still when we examine instances of what Skinner called “seeing without a thing seen" If I dream of a wolf, is a wolf present? If I imagine my childhood home, is my home there? Probably one reason copy theory exists is to try to explain such instances. Supposedly if I am seeing, something must be there to see; since neither a wolf nor a house is there, a copy must be held up somehow to my vision (not to my eyes!). Copy theory used this way is a form of mentalism; the apparent explanation is no explanation at all. Where is the ghostly mental copy, what is it made of, and how can it be seen? Whereas before we had an action of seeing to explain, now we have the same action plus a mysterious copy with a mysterious relationship to the action. The alternative is to consider seeing a wolf with eyes closed to resemble seeing a wolf with eyes open. The two activities differ—we can usually tell them apart—but they have much in common. This leaves unanswered such questions as, “How do I dream and imagine things I have never actually seen?” and “Is it possible to practice imagination?” Viewing dreaming and imagining as activities, however, allows these questions to be framed for scientific study more effectively than they could be by copy theory.
Copy theory attempts to explain dreaming and imagining by the idea that copies are stored in and retrieved from memory. Questions about recollection become questions about ghostly mental processes of encoding, storage, and retrieval. If when I imagine my childhood home I see my father there, supposedly that is because the two copies are somehow linked together in memory. If when someone says, “Think of birds,” I think of sparrows, finches, and ostriches, supposedly that is because copies of those things are linked in some way in memory.
In contrast, behavior analysis points to facts of life. When I was a child, seeing my childhood home, I saw my father, too. When I heard about birds, I often heard about sparrows, finches, and ostriches. If these things are linked, it is not in memory, but in time and place. Recollection is repetition. When I recall a visit to the ocean, I resee the sky, water, and sand, rehear the waves, and resmell the sea air. Those actions of imagining differ from the original actions of seeing, hearing, and smelling, but they are similar also. Much of our behavior is repeated every day. I comb my hair every morning. Does it help to understand how or why I do that to say that somewhere inside me must be a memory of hair combing?
Many psychologists cling to the idea that if an activity repeats, it must somehow be represented inside the person, presumably in the brain. When faced with the defects of representations as copies, they often insist that the representation is just the workings of the brain. By such reasoning, when I start my car each morning, the running engine must be represented in the resting engine. Someday, neurophysiologists may have something to say about the brain mechanisms by which activities recur. In the meantime, we can continue to expand our understanding of seeing and reseeing as activities.
Sensory activities are modified by experience; they are subject to learning. First- year medical students see a brain differently from their instructors. Once upon a time, the instructors saw as little as the students; someday the students will see as
Figure 3.1 Two "droodles." much as their instructors. We learn to pick things out of a landscape or a symphony. If I say to you, “See that barn across the fields” or “Listen to the oboe,” you see or hear something that you didn't a moment ago. Figure 3.1 shows two “droodles.” If you have never seen them before, they look like collections of lines. (If you have seen them before, then remember the first time you saw them.) Now I tell you that the top one shows a bear climbing a tree (it's on the other side), and the bottom one shows a soldier and his dog going behind a fence. You see them differently. Your behavior has changed as a result of reading these words. After we take up discrimination and stimulus control in chapters 6 and 7, you will understand better how this behavioral change could be called discriminated seeing.