Among the approximately 250 identified cognitive biases, some deserve consideration in the educational field. This is the case with the Pygmalion effect, which we have already discussed, influencing the relationship between teacher and learner and potentially having a significant impact on learning. Here are three particularly notable ones: the polarization blind spot bias, the halo effect, and the curse of knowledge.

Seeing the Speck in Your Neighbor’s Eye and Not Seeing the Beam in Your Own

Known as a bias blind spot, this bias is connected to a visual phenomenon we all know: an area of our retina lacking photoreceptors, rendering us blind to that part of our visual field. Cognitively, this means we are more apt to perceive the influence of cognitive biases in others rather than in ourselves. In reality, we are all subject to these biases.

This bias is often attributed to the value we place on information from introspection (Pronin and Kugler, 2007). Thus, when we evaluate our own thoughts, we favour internal information over our actions, while in judging others, we give more weight to their behaviours than to their thoughts, even if we are aware of them. This phenomenon, called the “introspection illusion,” stems from our need to preserve a positive self-image, complicating the acceptance of irrational judgments. Moreover, cognitive biases often act unconsciously, making introspection ineffective in countering them (Pronin, 2008).

In the teaching environment, the bias blind spot can lead a teacher to adopt attitudes toward learners that align with certain preconceived ideas they know to be false and would not apply to themselves. For example, one might think of stereotypes suggesting that boys are more gifted in certain types of learning (mathematics, sciences, sports, etc.) and girls in others (reading, writing, humanities, etc.); or those suggesting that people of certain origins are “naturally” better in certain subjects, such as Asians in mathematics and sciences.

Believing That Clothes Make the Man

Also referred to as the “notoriety” or “contamination” effect, the halo effect manifests when we form an overall opinion of a person based on just one of their characteristics. If this characteristic is perceived positively, we tend to view the person’s other attributes similarly, and vice versa if it is perceived negatively. This effect influences not only our perception of others but also our expectations of them.

A typical example of the halo effect is related to physical appearance. A study conducted in the 1970s among teachers revealed that they tended to judge a “beautiful” child as being more intelligent, more likely to succeed, and having parents more involved in their school activities than those judged less attractive (Clifford and Walster, 1973).

Grading assignments and exams indeed involve making judgments on learners’ performances (Durand and Chouinard, 2012), and any judgment can be biased (see The 3 Speeds of Thought). When possible, a solution is to opt for blind grading by asking learners to identify their work and exams with their student numbers rather than their names. Note that the halo effect can also originate from the presentation aspect of a work. Unless this criterion is being evaluated, the risks of the halo effect can be reduced by asking learners to present their work uniformly.

Hyper-specialized jargon for the untrained mind

Despite its intriguing name, the curse of knowledge is a relatively simple cognitive bias to identify… especially in others! It translates into difficulty in putting oneself in the place of someone who does not possess the same knowledge. This situation is often illustrated by experts using technical jargon that the general public does not understand. The curse of knowledge can also lead to difficulties in understanding the realities of non-experts and anticipating their reactions.

The more knowledge we acquire in a field, the easier it is to fall into abstraction unless we make a conscious effort to make the information accessible. Even if teachers are trained in simplification, the act of teaching multiplies the risks of succumbing to this bias. Moreover, factors like the age or educational level of students may lead teachers to reduce their efforts to simplify, which could discourage some learners—who may feel they don’t have what it takes to understand the material or even to pursue a career in a field that might have interested them but now seems impenetrable and out of reach.

Given the unfortunate effects this cognitive bias can have on learners’ trajectories, every teacher must be aware that despite their training in simplification, they too may fall prey to this curse of knowledge… Knowing is the first step to breaking the spell!