Horn Effect Bias

Confirmation Bias
Knowledge Center


Devayani Vyavaharkar
Student (University), Germany

Horn Effect Bias

The horn effect is one type of cognitive bias - more specifically one type of confirmation bias - that causes one's perception of another person to be unduly influenced by a single negative trait.
We tend to make negative judgements and assumptions about individuals by attributing it to a specific negative aspect of their trait, personality or appearance.
For example:
  • A newly appointed employee reflects aggressiveness while trying to complete his first assignment. He is easily assumed by his colleagues or supervisors as having an aggressive personality.
  • A superior displays rudeness towards an employee. This is generalized by employees to be the very nature of superiors towards their subordinates.
  • People are assuming a physically unattractive person is morally inferior to an attractive person (despite the lack of a scientific relationship between morality and physical appearance).
Why does the horn effect happen, and how can we avoid it?

What is the Horn Effect? Introduction

The term "horn" refers to the devil's horns. This is a metaphor, just like it's opposite, the Halo Effect Is doing. "Halo" refers to a saint's halo.
The Horn effect is the tendency to cause an individual's perception of another to be influenced dramatically by negative aspects of that individual. It is a type of cognitive bias that skews an individual's perception of another. However, an initial negative impression of a colleague or a superior should obviously not be generalized by considering it to be their sole feature. If the attention of people is diverted only towards the negative qualities, they tend to overlook the positive (and brighter side) of that individual. Thus, the inability to see 'beyond the horns' results in prejudice formation, favouritism and inequality in the workplace.

History of Horn Effect

The term Horn effect was first coined by Edward Thorndike in 1920. In his experiment, he asked officers to rate soldiers on various dimensions such as physical qualities, intellectual ability, character and leadership potential. The soldiers selected were those who had never interacted with the officers before. Just as Thorndike found the presence of halo effect (tendency to make specific inferences based on general observations) in the results, he also found the horn effect playing a predominant role. Officers who rated the soldiers negatively on one dimension displayed the tendency to rate them negatively across all the other dimensions.

Occurrences of the Horn Effect at Work

  1. Horn Effect in Selection of Employees: The Horn Effect often skews our judgements and eventually our decisions while selecting potential candidates for the company. There is a possibility that a single negative impression made by candidates due to their appearance or personality can result in ruling out these candidates which could actually have been the best ones.
    For example, candidates with an unusual hairstyle or dressing sense during an interview might be viewed less favourably, thus reducing their chances of being selected. Instead, the company might choose those candidates who are not or less fit for the respective positions.
  2. Horn Effect in Performance Appraisals: During a performance appraisal, a manager recalls that one instance where his/her subordinate did not perform well (for example: did not get the desired contract for the company). In such case, that employee is more likely to be reviewed negatively in spite of several achievements and profits that the employee might have made in the same period.
  3. Horn Effect in Projects and Work Assignments: If an employee performs poorly on one specific task, (for example: failed to give a compelling presentation) he or she is assumed by his manager and colleagues as deficient in that entire area of work. Consequently, without considering the reason behind the employee's poor performance in that specific task, the employee might be denied several opportunities in that area because of that single poorly performed task.

Steps to Eliminate the Horn Effect

  1. BEING AWARE OF THE EXISTENCE OF SUCH COGNITIVE BIASES helps in creating awareness and developing ways to tackle it effectively.
  2. It is crucial to understand that an overall impression of an individual cannot and should not be derived from one single factor, be it positive or negative. Hence, it is necessary to TAKE MORE INFORMATION AND MORE FACTORS INTO ACCOUNT in order to make a rational, unbiased decision.
  3. We often make decisions based on first impressions of people. It is important to CHALLENGE OURSELVES TO RECONSIDER OUR DECISIONS by giving everyone equal opportunities to thrive and reflect their true skills by keeping our assumptions aside.
In short, we all have expressed biased opinions in the past. In order to specifically tackle the horn effect, it is essential to look beyond the negative qualities of an individual, consider the positive qualities that lie within, and try to judge the individual without any distorted opinions.

⇒ What are your thoughts and experiences with respect to the horn effect? Please share your ideas and experiences below.

Bryan-Davis, A. (2019, June 24). "Halos & Horns In The Workplace". Retrieved December 29, 2020
Is the Halo and Horn Effect influencing your decisions at work? (2020, March 13). Retrieved December 29, 2020
What is the Horn Effect? - Human Relationships. (2019, April 01). Retrieved December 29, 2020
How can HR prevent the halo vs horns effect from creating tension at work? (2019, May 07). Retrieved December 29, 2020


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