Pilots - Are Two safer than One?

Group discussion affects pilot's perceived invulnerability (PI).

It is considered that pilots demonstrate PI and that this affects their ability to perceive risks appropriately. Lee & Gilbey examined the affects of group polarisation theory and whether this increased the level of pilots perceived invulnerability during multi crew flight operations in general aviation (2010). The study showed that although pilots had a high perceived level of invulnerability following discussion with another pilot they did not show increased levels of PI. Data file located here Pilots invulnerability perceptions in GA.
Further analysis of the results were made to identify if in fact PI decreased following discussion.


The study identified that pilots with high levels of PI showed a decrease in perceived invulnerability when measured in groups.

Individual vs Group Mean effect of group polarisation on PI interpretation
Individual 6.24 high
Group 6.01 lower

Below is the results of the statistical analysis that indicates pilots with the higher levels of PI when alone showed a reduction in PI when measured in groups. It also shows the ANOVA results that compared PI levels of individual and group scores against PI of a control condition.

Effect interpretation
Group polarisation on PI Significant
Interaction between manipulation (alone vs. group) and PI score in the control condition (low vs. high) High Significance


Research approach

  • This was a further exploratory study of the effect of group polarisation on PI of general aviation pilots.


  • A convenient sample of 78 General Aviation pilots participated in the original research. This was reduced to 58 pilots for this study as the nine pairs of participants in which one pilot did not demonstrate PI were excluded from all further analysis.
  • The original sample had the following demographics, a breakdown of the reduced sample demographics is not available. Female pilots (n=14) and male pilots (n = 64). Pilot ages varied between 18 and 59 years old (Mean = 25.94) and total flight hours between 30 minutes and 5,000 hours (Mean = 662.38).
  • Pilots were only chosen from flight training organisations. A significant proportion of other general aviation operation types were not included in the research.
  • Flight training is primarily conducted under a single pilot in command (instructor/student) and would not be considered multi crew flight operations.
  • Pilots with as little as 30 minutes flight time were used. Pilots of this very low experience level do not have any multi crew flight experience at all.


  • The dependant variable in the study was the level of perceived invulnerability.
  • Independent variables included: allowance of group discussion, pilot experience and pilot age.


  • Pilots were invited to undertake a two part questionnaire comprising of nine items. The items are unknown and may or may not have been aviation related.
  • The questionnaire required pilots to grade each item of invulnerability on a 9 point Likert-type scale.


  • Pilots from seven different flight training organisations in the North Island of New Zealand were sourced to conduct the questionnaire.
  • The first part required pilots to answer the questionnaire individually to determine each individual’s level of PI. In the second part pilots were told to discuss their individual answers to the questionnaire with one other pilot then following discussion repeat the same questionnaire to ascertain the variable.

Data analysis

  • Pilots were split into two groups based on a median split of their individual perceived invulnerability (>5.8 high, ≤5.8 = low).
  • A 2 x 2 ANOVA, between-subjects was used to establish if there was an interaction between manipulation (alone vs. group) and PI score in the control condition (low vs. high) to establish the effects on group polarisation on PI.
  • The significance threshold used is unknown.

Generalization potential

Given the exploratory approach of the research and the small sample and its convenience, the results from this study may not have enough scope for generalization. Results would only be applicable to pilots who belong to a flight training organisation in New Zealand.

  • The roles of the pilots in the study is not known. The sample could be comprised of predominately students and/or instructors and may therefore be generalized to that particular role.
1. LEE Seung Yong, GILBEY Andrew, (2011). Two pilots may be safer than one: The effect of group discussion on perceived invulnerability. Aviation Education and Research Proceedings, vol 2011, pp 43-44. ISSN 1176- 0729.
+++ Notes +++
2. ###

Want to know more?

Wikipedia - Group Polarisation
This Wikipedia page offers further information on Group polarisation

Aviation Knowledge - Dangerous team thinking styles in aviation
This Aviation Knowledge page provides further information on impacts of group polarisation from a different perspective.

Massey University - 2010 Symposium Proceedings: You can read further full articles by Andrew GILBEY, PEREZGONZALEZ Jose D & TANI Kawtar (2010).

Contributors to this page

Authors / Editors



Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License