Journal Club 5: V. Talanquer, When Atoms Want, Journal of Chemical Education, dx.doi.org/10.1021/ed400311x
How many of us have said something like the following when explaining why atoms form ions of a certain charge?
Sodium atoms want to lose one electron so that they can have a full electron shell.
Vincente Talanquer writes an interesting piece in Journal of Chemical Education this month on the (over)use of teleological explanations in science and chemistry education. A teleological explanation is one which uses the consequence of the event (to become more stable) to explain why the event happened (loss of electron). This is conferring a desire on the part of the sodium atom. I have to confess, I do this all the time, especially at introductory level.
Talanquer examined whether students chose teleological explanations to explain observations (they did, overwhelmingly), and also whether they chose teleological explanations over causal explanations. For example, a causal explanation for our dear sodium atom losing an electron would be:
Sodium atoms have one electron in a valence orbital with a higher energy than available valence orbitals in other atoms
Students chose teleological explanations over causal explanations in the range of questions posed. Finally, students over a range of levels (introductory to graduate) preferred teleological explanations.
The preference for teleological explanations is in part assigned to the fact that it offers a more easily understood explanation for an observed phenomenon, and as such learners are more likely to grasp onto it as a means of being asked to explain the observation. This probably explains why it is is prevalent at introductory teaching. However, Talanquer argues that their overuse might prevent students from examining the phenomenon more deeply; meaning that concepts such as equilibrium are difficult to understand. Talanquer writes:
Teleological explanations are problematic in education because they provide a cognitively cheap way of satisfying a need for explanation without having to engage in more complex mechanistic reasoning.
Therefore, in relying on teleological explanations, an event occurs because the substance involved wants it. This thought eliminates a more nuanced view of a process occurring, often in competition with other processes, which may cost more energetically, or be slower, and therefore less likely to occur. This probabilistic view is lost in the simplicity of the original explanation.
What to do?
I think these applications have a value, but perhaps as a first step in engaging learners into the fact that a particular observation is a routine occurrence (e.g. group 1 form 1+ charge). However, when we move on to more in-depth discussion, it’s important to bring learners along so that they don’t over-rely on their simplistic understanding. I think this probably aligns well with Bloom’s Taxonomy.
What do you think?
1. Do you use teleological explanations?
2. What value do you think they have, and do you agree with the arguments presented in the paper, that they may be overused?