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?
3 thoughts on “Atomic Desire: Teleological Explanations in Chemistry Education”
1. I use them all the time. I hadn’t really considered it problematic before but I suspect analysis of my lecture recordings would reveal a great deal of teleological explanations.
2. I’ve not read the paper(because I’m sneaking a quick bloggy break before heading off for more lab teaching fun), but I would agree with your ‘What to do?’ statement that using such statements is valid for students in the early stages of their chemistry education. It does indeed seem to align well with Bloom’s, and provides memorable ways to remember cause and effect relationships for simple knowledge and understanding. Attaching a human desire (‘want’ as per your first example) is perhaps a different problem, but that too can link concepts well for students. I do that too! I can see that both personification and teleological explanations are limited in more advanced teaching scenarios, but they are widely used tools in the media and science communication in general for a reason: they work. As our students develop more sophisticated vocabulary (‘valence orbital’ in your second example), we can push them into more sciency explanations and further up Bloom’s taxonomy. So I see no harm in using them in moderation and probably regard personification as a bigger issue.
1. Yes, I am very, very guilty of doing this, especially with less able students and those whose background science is limited. As Katherine says, they are very much used and very useful in science communication for general audiences and some of my students will be those general audiences as they will take chemistry no further than age 16.
2. Their value is in their accessibility; they provide a hook onto which further understanding can be hung (or not depending on where they choose to go with their chemistry). They are also a means to an end, they allow students to gain credit in examinations. Their weakness for me is that they are very difficult for students to let go of when they move through their chemistry education. I use them far less with 17/18 year olds (and this is a conscious decision I think) and am often confronted by them when tackling more advanced chemistry. Perhaps if there were no exams there would be less need for these explanations but I suspect we would all still use them, through habit and a desire for students to a handle on what we’re teaching them and also because as teachers we have a tendency to replicate how we were taught ourselves.
Thanks to you both for replies. I think we all agree that they have a place in terms of introducing students to material; and as things progress, we begin to introduce the underlying “whys”. I did gulp a bit when I read paper first, so it’s good to hear from you that they are a pragmatic way to introduce topics to students…!
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