The Elephant's Trunk - and Other True Stories
Identifying and addressing the underlying causes behind misconceptions in biology
Common misconceptions in biology
It is fair to say that most students of biology do not subscribe to the view that the elephant’s famous trunk is the result of a tug-of-war with a crocodile, as told in the children’s Just So Stories! The trunk evolved, over time, by the process of natural selection. There are, however, a number of common misconceptions about evolution and other topics that are held among biology students, even biology majors. It is interesting to delve into what lies behind these misconceptions and to explore ways to address them, in order to gain insights as to how we might improve science communication.
A number of misconceptions are related to the theory of evolution, not least that it is ‘just a theory’, which arises from the distinction between the word ‘theory’ as it is used in everyday speech versus the scientific definition of a theory, which is a body of evidence supported by numerous observations and experiments. Another misconception around evolution is the idea that an organism ‘adapts itself’ to its environment. For example, it is not uncommon for a student to write something along the lines of: ‘As the ancestors of dolphins spent more time living near water, they adapted themselves to an aquatic lifestyle, grew flippers, and developed a blowhole on the top of their head’. The key misconception here is that the ancestral dolphins adapted themselves in some kind of directed way as if they were predicting the need for such features, which would afford them an advantage as they moved into their new, watery environment. Evolution, however, is a process which has no forward planning and no directed outcomes; some organisms are well-suited to their environment — they survive, reproduce, and pass their successful genes on to the next generation — but there is no foresight involved in this process.
The misconceptions I have described are examples of what educational psychologists refer to as ‘cognitive construals’ — the informal views of the world and phenomena that individuals hold, based on their own assumptions and particular ways of thinking. It is one of the challenges in biology education, and science communication more generally, to address these cognitive construals when they occur and be able to provide clear, rational explanations as to why these construals are not correct from a scientific perspective.
The cognitive psychologists John Coley and Kimberley Tanner identified three common underlying causes of misconceived cognitive construals: teleological thinking, essentialist thinking, and anthropocentric thinking, and examples of each of these are outlined below.
1. Teleological thinking
The first underlying cause of misconceived cognitive construals, known as teleological thinking, refers to our very human need for causal stories behind the observations we make of phenomena around us, based on an assumption of goals, purposes or functions. An example of teleological thinking is one of those described above, where a student assumed that a dolphin ancestor made a purposeful effort to change itself into a form more suited to a life aquatic. Another example would be that cheetahs ‘adapted themselves’ to run faster in order to catch their fast-moving prey, whereas what actually occurred was that natural variation in the cheetah population meant that those individuals who could run faster had an adaptive advantage, survived to reproduce, and passed on their advantageous genes to their offspring.
2. Essentialist thinking
The second type of common misconception is related to essentialist thinking — a set of assumptions that an individual may make about concepts, such as the idea that a particular feature of a system is solely responsible for defining its overall identity. An example of this would be the misconception that different cells in our body have different DNA whereas, in fact, all of our cells contain the same DNA, but not all of the same genes are activated in all of our different cells. Another example of essentialist thinking is the misconception that all plants are photosynthetic. This is not true. For example, Rafflesia, the plant which produces the largest flower in the world, is parasitic and therefore does not carry out photosynthesis to make its own food. In biology there are frequently exceptions to every ‘rule’, thus we need to find ways to move beyond the idea that systems or processes must be defined by a particular characteristic that most of them share.
3. Anthropocentric thinking
The third misconception occurs when biological phenomena are viewed through an anthropocentric, or human-centered lens, where we ascribe human values or characteristics to non-human subjects. A common anthropocentric misconception is that plants take in food from the soil via their roots. It is easy to see how underlying, anthropocentric reasons for this misconception may arise — we think that all organisms, including plants, must ‘eat’ food, and that they, therefore, must do this in a way similar to humans. We are also sold essential micronutrients that plants do need to take in from the soil, and which are often referred to as ‘plant food’, that we then give to our potted plants. In reality, plants take in the raw material for their food — carbon dioxide — from the air. This misconception can be addressed by asking why, if plants take in their food from the soil, are there not then enormous holes in the ground at the base of every tree in a park or garden?
From my perspective as a biology educator, I am interested in what lies behind these commonly held misconceptions so that I can help my students to address them and begin to think in a more scientific way. I work with students who have English as an additional language, so they in some ways face a greater challenge than students who are learning science in their first language. This makes it even more important for me to consider ways to address these misconceptions explicitly, at an early stage of the teaching and learning process.
I can understand — and have sympathy with — how these three types of thinking may lead to misconceptions around scientific ideas, and I think this type of insight is important in order to develop approaches to successfully dispel these ways of thinking.
As humans, we naturally feel a need for something to have a purpose or a reason — such as thinking that the cheetah needed to be able to run faster to catch its prey, and so it made a conscious decision to become a faster runner. This is the way our mind likes to think, and sometimes it catches us out. It is important therefore to re-state the fact that adaptive and evolutionary processes have no foresight.
Essentialist thinking leads us to want to have everything in neat, easily classifiable categories. This is something I have observed many students have a major problem with — often they are unhappy with the idea that some things just are not easily classifiable, for example, are viruses living or non-living, or something in between? It is necessary to point out that there are grey areas, that sometimes it is not possible to neatly categorize all things.
Anthropocentric thinking is in many respects even easier to understand — humans have a tendency to feel that we are the most important feature of any given situation, and we can therefore easily fall into the trap of ascribing human values and attributes to non-human, or even non-living, things. This is probably not helped by the large numbers of talking animals and cars to be found in children’s cartoons! Students can be helped past this point by being reminded that humans are not, in fact, the center of the universe.
The insights afforded by understanding the underlying causes of common misconceptions among biology students are both interesting and helpful. Interesting, in that these misconceptions would appear to be widespread, irrespective of culture or language (although there may, of course, be some communities where they may not be present), and helpful, in that by understanding the underlying causes of these misconceptions, this may provide science communicators with various effective means with which to address them. Understanding how these misconceptions may arise can give us clues as to how to go about addressing them in a constructive, plain language, but a non-patronising way. In turn, once individuals become more aware of the underlying causes of common misconceptions, they too may be able to spot them more easily and avoid falling into these common traps.