For students to understand an object of learning in the way a teacher intends, we must not only identify but also resolve students’ misconceptions (Hewson & Hewson, 1984). Following Siegler (1983), it is not enough to provide students with an experience that disconfirms their alternative view, we must also provide them with the opportunity to reconceptualize the object of learning. To understand how to provide students with this opportunity, it is important to understand the basis of conceptual conflict. First, students need to be presented with two theories (or conceptions) that they understand—including one constructed from their prior knowledge—to explain a phenomenon. They must recognize that the two theories are inconsistent with one another and that one theory is more plausible. Teachers can show students that a new theory has broader applicability or more predictive power (i.e. is more fruitful)  than the students’ previously held concept; thus, increasing the new theory’s plausibility and providing conceptual conflict. Students can then either compartmentalize the two concepts and differentially apply them to distinct situations or reject one theory in favour of the other. Note that if a teacher does not present the new theory in a way that is accessible to the students, it is unlikely that the students will reject their initial conceptualization in favour of the new theory (Hewson & Hewson, 1984). Thus, teachers require a tool that can reliably identify students’ prior knowledge, demonstrate the intelligibility, plausibility and fruitfulness of a novel theory, incite conceptual conflict, and promote conceptual change. I suggest that Variation Theory (VT) can be extended to provide such a tool.

I will walk through an example of how educators can apply the concept of unifying aspects to promote conceptual change with respect to Evolutionary Theory (ET). Among high school students, one of the most prevalent misconceptions about ET I have experienced is that humans are the “most evolved” species. I am able to identify this misconception when introducing ET because I begin my lesson by probing for students’ prior knowledge. I will usually start by asking students to provide examples of “higher and lower” organisms and then ranking them on the board. Importantly, I do not provide the students with any criteria for ranking the organisms as “higher” or “lower”, this is up to the students to decide. Most often, students will rank humans as the “highest” organism, which prompts me to ask the students why they ordered humans above monkeys, fishes, rodents, insects, and all of the other organisms on our list. Students usually justify their decision by asserting that humans are the most intelligent and, therefore, the most evolved organism. I am now able to identify students’ misconception that ET is intrinsically linked to intelligence and my instructional goal becomes separating the concept of intelligence from the concept of evolution.

Because we are exploring two independent concepts (i.e. two independent objects of learning) I need to create unique patterns of variation for introducing intelligence and evolution. Yet, how I want students to apply the concept of evolution informs the features I get them to focus on when exploring intelligence. As a result, I would vary the following aspects of intelligence:

1. Types of intelligence — among which planning, problem solving, memory, and self-awareness are all values (Shettleworth, 2009);
2. Advantages of intelligence — among which escaping from predators, locating critical resources, reacting to environmental stochasticity, and securing mates are all values (Dukas, 2009);
3. Disadvantages of intelligence — among which high energetic cost is a value (Parker, 1990); and
4. Intelligence as a heritable trait — among which genetic and environmental factors are values (Dukas, 2009).

The purpose of this pattern of variation is to have students focus on critical aspects of intelligence that allow them to apply the concept of intelligence to the concept of evolution. By exposing students to variation within each of these critical aspects I have given them the ability to apply the concept of intelligence to the concept of evolution in multiple ways. Now I can vary the following aspects of evolution:

1. Ability to survive — among which ability to escape predators, ability to avoid danger, and ability to locate critical resources are all values (Endler, 1986);
2. Ability to reproduce — among which ability to locate mates, ability to attract mates and ability to successfully rear offspring are all values (Endler, 1986).
3. Ability to pass on successful traits — among which number of successful matings, and heritability of advantageous traits are values (Endler, 1986).

Now that students have been introduced independently to each concept and are subconsciously aware of critical aspects that unite intelligence and evolution, I can bring the students’ awareness of these aspects to the fore. My object of learning now becomes ‘understanding intelligence as an evolutionary trait’ and my unifying aspects become:

1. How intelligence influences survival — among which an increased ability to escape predators, avoid danger, and locate critical resources, as well as a decreased ability to meet energy costs are all values (Amiel et al., 2010);
2. How intelligence influences reproduction — among which an increased ability to locate mates and successfully rear offspring, as well as a decreased ability to produce gametes are all values (Amiel et al. 2010); and
3. Factors influencing the heritability of intelligence — among which ability to pass on  traits that make intelligence advantageous is a value (Amiel et al., 2010).

I can now vary these unifying aspects to explore students’ alternative conception that more intelligent animals are evolutionarily superior to less intelligent animals.

For instance, I could present an example where an intelligent female bird is able to successfully rear more chicks than her female conspecifics because she is a more efficient problem solver, a trait that is heritable and passed on to her offspring. This results in the intelligent female bird’s alleles increasing in frequency within the population and, thus, the net intelligence of the population increases. If the trend towards more efficient problem-solving continues, this species of bird will evolve greater intelligence. This example actually confirms the students’ belief that evolution is intrinsically linked to intelligence and reinforces the idea that humans are evolutionarily superior to other organisms. If I stopped my exercise here, many students would leave thinking I had wasted a lot of time speaking in great depth about intelligence and evolution, only to tell them something that they already knew (Hewson & Hewson, 1984). However, I could use the same unifying aspects to introduce an alternative example and generate conceptual conflict, which can alter students’ understanding of evolutionary theory.

One such example would be to describe an immature male bird that has a hippocampus (the area of the brain associated with learning and memory) twice the size of any of his conspecifics. This makes the bird highly intelligent, so that he can store and memorize the location of far more nuts and seeds than any other bird. However, the increased brain mass also adds 1% to his body mass. While this mutation seems advantageous, the increased body mass actually reduces the bird’s flight efficiency by a factor of 5%, making him marginally slower than other birds. As a result, the intelligent bird cannot keep pace with conspecifics in his flock and he is easily caught by a predator. This demonstrates a potential trade-off between intelligence and body mass for birds—where the benefits of added brain mass to intelligence are vastly outweighed by its cost to flight efficiency. Because the male bird died before he was able to reproduce, his alleles for greater brain size were eliminated from the population. In this case, having a larger brain and greater intelligence actually put the bird at a disadvantage. This example shows students that greater intelligence, as an evolutionary trait, is not always advantageous—information which is counter to their alternative conception of evolution. Once I had generated the disconfirming experience, I would give students the opportunity to reconcile the conflict between their alternative concept and the concept I had introduced. For this to occur, I need to make sure that students find the new concept intelligible, plausible, and fruitful (Hewson & Hewson, 1984). At this point, I would use a check for understanding that required students to access higher order cognitive processes (such as creation, evaluation or synthesis; Anderson et al., 2001) to ensure that students had successfully experienced conceptual change.

The use of VT as I have described it here, including the use of unifying aspects, meets all of the conditions for conceptual conflict (Hewson & Hewson, 1984):

As well as meeting the conditions for conceptual conflict, VT also meets the conditions for conceptual change. By sequentially introducing students to intelligence and evolution as independent concepts and then explicitly linking the two through unifying aspects, I can ensure that students are focusing on the critical aspects of each concept that will help them find my version of ET intelligible, plausible and fruitful. Students are more likely to reject the alternative concept and exchange it for the generally accepted concept once they see that the new theory has broader predictive power (Hewson & Hewson, 1984). As I have demonstrated, Variation Theory not only provides the means to produce conceptual conflict and promote conceptual change, it provides sound support for the use of conceptual conflict as a pedagogical tool.