But I Thought I Knew That!

“We are infected by our own misunderstanding of how our own minds work.”
Kevin Kelly


Over the last several decades we have learned a lot about teaching and learning.  One of the most critical things with regards to education is the addition of new information to memory. The storage of new information in memory and our understanding of that information is dependent on what we already know. According to Jean Piaget’s Cognitive theory, three critical components of learning depend on preexisting knowledge Equilibrium, Assimilation, and Accommodation.

In Piaget’s modal assimilation occurs when the new information matches a learner’s preexisting views and without changing can be incorporated into their view.  Accommodation happens when new knowledge conflicts with the learner’s preexisting view of the world, in this case, the student’s view must change to incorporate the new knowledge.  Equilibrium is the condition where most new knowledge can be dealt with by the students existing view.

In simpler terms, preexisting knowledge can either help or hinder a student’s learning.  If the preexisting knowledge aligns with the existing knowledge, it helps, when the current information does not align with existing knowledge it hinders.

PriorKnowledge_Combined Files-1

Modified From: Exploring Research-based Principles of Learning and Their Connection to Teaching, Dr. Susan Ambrose

Since no student is a blank slate, they will always have a view based on their own life experiences.  When a student learns something that does not fit their view, either their view must change (accommodation), or the new information is altered to fit their view (incorrect assimilation).

In modern education, we call these incorrect views a misconception.  To overcome misconception so that accommodation can occur students must actively acknowledge their misconceptions.  These misconceptions can be especially impactful in science education where many of the ideas taught can’t be touched or physically observed.

In chemistry, we teach students about atoms and molecules, which are too small to see or feel. In astronomy, we teach students that the earth is orbiting around the sun at 67,000 miles per hour.  However, do we feel that speed on the surface of the planet?

Beyond misconceptions derived from observations, students can also acquire misconceptions from language.  In the field of genetics, a common misconception is: A dominant mutation is the most likely one to be found in the population. This misconception likely comes from the word dominant which has six definitions according to the Marian-Webster dictionary.


  1. a: commanding, controlling, or prevailing over all others the dominant culture
    b: very important, powerful, or successful a dominant theme a dominant industry the team’s dominant performance
  2. overlooking and commanding from a superior position a dominant hill
  3. of, relating to, or exerting ecological or genetic dominance dominant genes dominant and recessive traits
  4. biology: being the one of a pair of bodily structures that is the more effective or predominant in action dominant eye used her dominant hand
  5. music: the fifth tone of a major or minor scale (see scale entry six sense 2)
  6. a: genetics: a character or factor that exerts genetic dominance (see dominance sense 1b)
    b: ecology: any of one or more kinds of organism (such as a species) in an ecological community that exerts a controlling influence on the environment and thereby largely determines what other kinds of organisms are present dominant conifers
    c: sociology: an individual having a controlling, prevailing, or powerful position in a social hierarchy: a dominant (see dominant entry one sense 1) individual in a social hierarchy

Most of the definitions have to do with importance, power, and control, which is likely why students think a dominant mutation is the most likely one to be found in a population.  However, there is another genetic term for the most common allele in a population, wild-type.  In genetics the term dominant must always be used about something else, for example, the phenotype of the dominant allele B is expressed instead of allele b.

I have always preferred to use the five-terms established by Hermann Muller to classify the specific types of genetic mutations over general terms like dominant and recessive.  Regardless of the words used, the students need to understand that we are discussing mutations that change the function of genes which has nothing to do with a mutation’s frequency in a population.

Another common genetic misconception is that all mutations are harmful.  At the DNA level, a mutation is simply a change to the DNA, a lot of mutations do not affect.  As an example, if a mutation occurred in a coding region, there is a good chance it will not change the final product.  If the mutation occurred in the third position of the alanine codon GCT and became GCC, it would still code for alanine, in fact, all four GCx codons GCT, GCC, GCA, and GCG code for alanine. That means any change in the third position of this triplet will not affect the protein formed. There are a lot of other misconceptions in genetics, but that is a discussion for another day.

When it comes to helping students deal with their misconceptions, it can help to try and understand where the misconceptions came from, and what might be influencing them.  As a faculty member once said, “If you want to understand what a student is thinking, ask them.”  If a student does not comprehend new information, it might be because of previous notions.  Learning what the student’s assumptions are and how the assumptions are interfering with the students learning will only make you a better teacher.


Thanks for Listening To my Musings

The Teaching Cyborg

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