Background shifts affect explanatory style: how a pragmatic theory of explanation accounts for background effects in the generation of explanations

Abstract

Cognitive scientists are interested in explanation because it provides a window into the cognition that underlies one’s understanding of the world. We argue that the study of explanation has tended to focus on what makes an explanation “bona fide” as opposed to the processes involved in how the explanation is generated. In the current study, we asked participants to respond to the request for an explanation within a novel domain after we manipulated their initial exposure to the domain, and thus the background of the request. In two experiments, we found evidence that the background shaped participants’ interpretations of the prompt for the explanation and that this, in turn, influenced whether they used a causal or functional style of explanation when responding to the prompt. We also asked participants to evaluate a number of explanations and found that the manipulation of the background did not have the same effect on the evaluative tasks. Our data support a pragmatic approach (e.g. The scientific image. Oxford University Press, Oxford, 1980) to the study of explanation generation, a philosophical approach which argues that the background influences the interpretation of the question, the development of a relevance relation which connects the question and explanation, and the identification of some set of candidate answers. We also suggest there is an important difference between the process of generating an explanation and evaluating an explanation, a difference that has escaped the attention of cognitive scientists thus far.

Appendices

Appendix A

A.1. Explanations used in the selection task: Experiment 1

• Causal “The motion of the odd-shaped thing initiated a sequence of events that ultimately resulted in yellow stuff coming out of the tall beaker”.

• Functional “The odd-shaped thing pushed a platform in order to get some yellow stuff out of the tall beaker.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Wrong “The beaker shattered after the lever hit, the platform melted, and purple stuff spilled all over the balloon.”

A.2. Explanations used in the rating task: Experiment 1

• Causal “The motion of the odd-shaped thing initiated a sequence of events that ultimately resulted in yellow stuff coming out of a tall beaker.”

• Causal chain “The odd-shaped thing moved a platform that led to the balloon compressing which led to the lever opening the door which in turn enabled the yellow stuff to come out of a beaker.”

• Causal analogy “The whole scene made me think of body parts. The long muscle-type thing would move, causing another body part to compress. This compression eventually led to the release of some kind of bodily fluid.”

• Cummins functional “To accomplish the system’s goal, the balloon has to move the lever, and the lever has to move the door so that the yellow stuff can come out.”

• Wright functional “The balloon exists so the lever will move—the lever exists so the door will open—the door exists so that the yellow stuff can come out.”

• Functional analogy “The whole scene made me think of a body-like system. A long muscle-type thing squeezed another body part in order to release some kind of bodily fluid.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Design “Yellow stuff is supposed to come out because the system was designed that way.”

• Desire “The odd-shaped thing pushed the platform because that is what it wanted to do.”

• Goal “The odd-shaped thing pushed a platform in order to get some yellow stuff out of a tall beaker.”

• Possible “The odd-shaped thing was strong—the ball was flexible—the lever was long and rigid—the yellow stuff was drippy.”

• Wrong “The beaker shattered after the lever hit it. The platform melted, and the purple stuff spilled all over the balloon.”

A.3. Explanations used in the selection task: Experiment 2, complete conditions

• Causal “The thing pushed the balloon, which moved the red lever. This movement caused the beaker door to open and yellow stuff to spill out.”

• Functional “The thing pushed the balloon in order to move the red lever and open the beaker door. The beaker door needs to open so the yellow stuff can come out.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Wrong “The beaker shattered after the lever hit, the platform melted, and purple stuff spilled all over the balloon.”

A.4. Explanations used in the rating task: Experiment 2, complete conditions

• Causal “The thing pushed the balloon, which moved the red lever. This movement caused the beaker door to open and yellow stuff to spill out.”

• Biological causal analogy “The whole scene made me think of a series of body parts. The thing moved, prompting the blue, lung-like thing to compress, and this compression eventually caused the release of some bodily fluid.”

• Mechanical causal analogy “The whole scene made me think of a series of engine parts. The piston part moved, prompting the blue part to compress. This compression eventually caused the release of some kind of fuel.”

• Cummins functional “The thing pushed the balloon in order to move the red lever and open the beaker door. The beaker door needs to open so the yellow stuff can come out.”

• Wright functional “The balloon exists so the lever will move. The lever exists so the door will open. And the door exists so that the yellow stuff can come out.”

• Biological functional analogy “The whole scene made me think of a bodily system. In order to get the bodily fluid where it needs to go, the thing has to push against a blue, lung-like thing.”

• Mechanical functional analogy “The whole scene made me think of an engine system. In order to get the fuel to where it needs to go, the piston has to squeeze a blue part.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Design “Yellow stuff is supposed to come out because the system was designed that way.”

• Desire “The thing pushed the balloon because that is what it wanted to do.”

• Wrong “The beaker shattered after the lever hit it. The platform melted, and the purple stuff spilled all over the balloon.”

A.5. Explanations used in the selection task: Experiment 2, broken conditions

• Causal “The thing pushed the balloon, which moved the red lever. This movement caused the string to break. Nothing happened to the yellow stuff.”

• Functional “The thing pushed the balloon in order to move the red lever, which was supposed to open the beaker door to get the yellow stuff out, but the string broke.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Wrong “The beaker shattered after the lever hit, the platform melted, and purple stuff spilled all over the balloon.”

A.6. Explanations used in the rating task: Experiment 2, broken conditions

• Causal “The thing pushed the balloon, which moved the red lever. This movement caused the string to break. Nothing happened to the yellow stuff.”

• Biological causal analogy “The whole scene made me think of a series of body parts. The thing moved, prompting the blue, lung-like thing to compress and break the string.”

• Mechanical causal analogy “The whole scene made me think of a series of engine parts. The piston part moved, prompting the blue part to compress. This compression caused the string to break.”

• Cummins functional “The thing pushed the balloon in order to move the red lever, which was supposed to open the beaker door to get the yellow stuff out, but the string broke.”

• Wright functional “The balloon exists so the lever will move. The lever exists so the door will open. And the door exists so that the yellow stuff can come out. But in this clip, there was no reason for the string’s existence”

• Biological functional analogy “The whole scene made me think of a bodily system. In order to get the bodily fluid where it needs to go, the thing has to push against a blue, lung-like thing. But in this clip, the system broke down.”

• Mechanical functional analogy “The whole scene made me think of an engine system. In order to get the fuel to where it needs to go, the piston has to squeeze a blue part. But in this clip, the system broke down.”

• Description “The balloon was blue. The lever was red. The stuff in the beaker was yellow.”

• Design “Yellow stuff is supposed to come out because the system was designed that way, but in this clip, the system broke down.”

• Desire “The thing pushed the balloon because that is what it wanted to do.”

• Wrong “The beaker shattered after the lever hit it. The platform melted, and the purple stuff spilled all over the balloon.”

Appendix B

B.1. Example explanations generated by participants in Experiment 1

Systematic condition

“In the previous clip, the plant-like thing that was using the ball and the board to feed itself, didn’t utilize gravity like it had in the previous two, and because of that it couldn’t get food and couldn’t replenish its energy source which means it couldn’t replenish itself with energy and because of that it didn’t have the energy to push the ball again and continue to receive food” (functional explanation).

“The thing did not exert enough energy to move the ball in order to connect to the other cables so that it did not get to the food, or whatever, and it did not have the energy to repeat the action” (functional explanation).

“From what I saw, a large colorful blob pushed the rectangle into the blue ball. Because the ball couldn’t, well its space was limited so it couldn’t expand to the right, so it expanded up and down into an oval which bumped into… I think it was a bar, a red one. Well the bar went up—well the left side of the bar went up, so obviously the right side went down and pulled on a string that was connected to a pulley that pulled up on… that triggered the object on the right to release some yellow liquid” (causal explanation).

Non-systematic condition

“The creature pushes a block so the ball flexes, and the ball flexing pushes a lever which pulls a string, and this causes another block to pull up… um… which releases the fluid outside of the ball” (causal explanation).

“I think that the object that is creating the initial force is pushing down on a block of some sort which pulls a lever or pulley which then makes some kind of liquid come out” (causal explanation).

“I think the clip was about some alien animal with a trunk pressing the lever to get some lemonade out of like the dispenser then it’s gonna slurp it up with its trunk” (functional explanation).

B.2. Example explanations generated by participants in Experiment 2

Systematic/complete condition

“Um, in this there is a lever that is pressed on a ball, and when the ball is squeezed there is another lever that is allowing um, some sort of door to be lifted, and there’s a material that spills out” (causal explanation).

“Well, I saw some sort of lever system that failed compared to the past previous systems” (functional explanation).

“Um, so in the last clip it looks like the machine isn’t working properly. In all of the previous ones um, there was something that pushed on like, the ball which released either another ball or blob into the machine and then fire came out and then the thing just kept going. But in the last one um, the—the machine was too far away or something and it didn’t work right because the fire didn’t start” (functional explanation).

Systematic/broken condition

“Is it recording me now? Click here when I’m done with it? Ok. For the (clears throat) final clip that was just shown the, it looked like a—possibly a hydraulic press or something that pushed the ball or the balloon to the pink little lever. However, as the lever—as the ball hit the lever and the lever would pull on a string, the string broke to where the yellow liquid—the string would open up the gate to the yellow liquid and it looked like the yellow liquid, if the string would not have broken, would have came out through the gate and then onto the—would have somewhat squirted across onto the little pad to where I’m assuming the yellow liquid would then go down the pad. The pad was kind of connected to a—a tube or a tunnel. And uh, I’m assuming the yellow liquid would then turn on the fire that would happen to restart the process again like the previous movies” (causal explanation).

“Um, the first video showed um, a series of processes that ended in, like a machine type thing that ended in something happening such as a ball dropping or something that appeared like liquid. But, the last one, it was clear that it was broken. So, when the red lever was touched the rest of the mechanism did not work” (functional explanation).

Non-systematic/complete condition

“Um, well, there was some sort of um, a lever that pressed into um, a round blue object, maybe a um, some sort of ball that um, is kinda um, squished and then it expanded to press a different lever um, which in turn um, made some sort of yellow liquid um, spill out of a container um, because when the lever was moved um, the yellow liquid could fall out of the container that was holding it. Um, and uh, basically one reaction just caused another and the movement of one lever or ball caused the movement of a different lever. Um, and the start of the movement of the ball commuted the spillage of the yellow liquid at the end” (causal explanation).

“Do I just start now? Um, it looks like it’s some sort of mechanism to some sort of machine or some type of thing to make something. Um, it looks like there’s a series of um, different mechanisms to allow that yellow—what looks like to be fluid to come out” (functional explanation).

“Um, the square moves the circle which moves the red lever and lets out some liquid” (causal explanation).

Non-systematic/broken condition

“Well I feel the uh, last film was similar to the first but, the uh, it was a little bit more simple. It actually reminded me of simple machines from like, a science class and there was a lot more action going on in the first few and the uh, last film depicts a little bit less action in what was going on” (no explanation—description).

“Um, the—a force pushed on a like, balloon or ball, which was supposed to trigger a pulley system, but the string was broken so it couldn’t um, release whatever was supposed to um, drive the force, I guess” (functional explanation).

“The previous clip um, showed a bubble thing filling up in order to get some yellow liquid out of a container. It looks like it was supposed to lift up a, um, like little door to the container but, um, one of the sections um, broke off in the middle therefore causing it not to fulfill its function. Um, and basically the balloon thing just sort of stopped, um, and the machine stopped” (functional explanation).