The armrest has become a flashpoint for the issue of the lack of personal space on the plane.

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Tags: airplane interior, proxemics,
materials, psychology


Design Decisions

The armrest is a structure that provides support for the forearm at the side of chairs and sofas, a feature so ubiquitous that it rarely draws much attention. In the airplane context, however, the armrest has gained an outsized symbolic importance in the passenger experience. As airlines move toward more tightly packed seating arrangements, the armrest has become a flashpoint for the issue of the lack of personal space on the plane. The seemingly small question of who gets to use which armrest has provoked numerous “armrest wars” among adjacent passengers, and intensified resentment among the economy class passengers toward fellow passengers and airline companies.

Patent for airplane seats showing ambiguity of armrest spatial “ownership” for middle seats.

The current design constraints for armrests primarily relate to issues of safety in the event of crash landing, material wear and tear, and spatial maximization.

1) Safety: The armrest, which can be moved up or down, is required to be down during take off or landing, and a hinge lock keeps the armrest in the down position [1]. This ensures that the armrest does not slam into the passenger in the event of a crash.

2) Material: The material must be highly abrasion resistant, as the armrest is one of the most high-touch surfaces on the plane. Thermoplastic polyurethane is a popular material option for this reason, a type of plastic with abrasion-resistant, UV-resistant, chemical-resistant, and elastic properties [2]. 

3) Spatial Maximization: The decision to have a single shared armrest between two seats in the economy class is a response to financial pressures to fit more passengers in the aircraft. First class and business class seats rarely have shared armrests, or other such ambiguity about the boundaries of a passenger’s personal space.

Effects on Passengers

Personal space has been defined as "the emotionally tinged zone around the human body that people feel is their space" where individuals feel a sense of ownership and any intrusion of it leads to feelings of discomfort, stress, and avoidance [3,4]. The armrest problem has come to symbolize the issue of the lack of personal space on the plane, as the most visible part of the much larger problem. The variety of personal space encroachments that passengers undergo can include bodily noise, undesired conversations, undesired gaze, smells, physical contact, and physical proximity. The outsized emotional reaction to armrest intrusion is likely not just about the armrest, but rather the accumulation of physical discomfort created by all of these intrusions.

“Terms such as ‘claustrophobia’, ‘cramped’, ‘closed in’, ‘constricted’ and ‘fidgety’ were associated with physical spatial invasions, including use of the shared armrest and outstretched legs.”4

This is further compounded by factors unique to air travel, specifically the increased difficulty in removing oneself from uncomfortable situations, and the increase in the amount of time one may need to tolerate personal space invasions. This creates higher levels of stress about the prospect of direct confrontation. leading many people to employ non-direct coping strategies from dropping hints, passively reclaiming space, to ignoring the issue and distracting oneself [4]. Even in a non-airplane context, it is unusual for people to confront others directly about space intrusions [5]. This may explain the popularity of semi-humorous lists of passive-aggressive strategies to take during “armrest wars”, as people fantasize about how they could have responded in past situations [6]. 

“Since you can't confront your neighbor any more than you can ignore him, you're left with one option: cunning. If your seat partner is violating your personal space, return the favor…subtly. Drop something on the ground near them, and ask them to pick it up. Either they’ll pick it up, removing their arm from the armrest, and you’ll be able to swoop in—or they won’t, and then you’ll know you’re seated next to a sociopath, which seems like a good tidbit to file away”6

Lastly, the presence of physical and situational inequality on airplanes have been shown to increase incidents of outbursts and “air rage” [7].  It is possible that the knowledge that the armrest problem is specific to the economy class, and that passengers in the first class and business class have the luxury of larger and more clearly defined personal space, might increase the likelihood of emotional outbursts and negative feelings.


What if armrests were shareable without physical contact?

Numerous designers have attempted to solve the so-called “armrest problem”. Soarigami has created a foldable attachment that is placed on the airplane armrest. Soarigami’s attachment provides a barrier and two flat surfaces for the person in the middle seat and the person next to the middle seat. The barrier blocks uncomfortable contact with the person next to you while letting you have an armrest [8]. Another proposed solution, from Paperclip Design, is a double-deckered armrest. Adjacent passengers can share the armrest without uncomfortable contact, as the single armrest loops to create two levels [9].

Paperclip’s double decker armrest design

Soarigami’s armrest splitter design

What if economy class seats offered more space, with a more defined personal space boundaries?

Business and first class seats have more defined personal space boundaries than economy class seats, and this contributes significantly to their passengers’ comfort levels. The middle seat armrest problem only exists because of cabin densification in the economy class. In the wake of the Covid-19 pandemic, fewer people are traveling altogether and airlines are offering more luxuries and ticket flexibilities to attract more passengers. This may be a rare opportunity for the economy class seating to de-densify.

De-densified economy class seating due to COVID-19
  1. Ferguson, Keith, and Donald Pinkal. 2012. Aircraft seat with adjustable armrest. US, Europe US8146999B2, EP2292512B1, filed 2009, and issued 2012.
  2. BASF Aerospace. n.d. “Aerospace Materials and Technologies Overview.” BASF Aerospace Materials and Technologies. Accessed June 2, 2020.
  3. Sommer, Robert. 2002. “Personal Space in a Digital Age.” In Handbook of Environmental Psychology, edited by Robert Bechtel and Arza Churchman, 647–60. John Wiley & Sons, Inc.
  4. Lewis, Laura, Harshada Patel, Mirabelle D’Cruz, and Sue Cobb. 2017. “What Makes a Space Invader? Passenger Perceptions of Personal Space Invasion in Aircraft Travel.” Ergonomics 60 (11): 1461–70.
  5. Felipe, N.J., and Sommer, R. 1966. "Invasions of Personal Space." in Social Problems 14 (2): 206-214.
  6. Skipper, Clay. 2017. “How to Win the Airplane Armrest Battle Once and For All: A Passive Aggressive Struggle as Old as...Planes.” GQ, October 23, 2017.
  7. DeCelles, Katherine A., and Michael I. Norton. 2016. “Physical and Situational Inequality on Airplanes Predicts Air Rage.” Proceedings of the National Academy of Sciences 113 (20): 5588–91.
  8. Ku, Caroline. “Extendable Armrests and Elbow Room for Two - APEX: Airline Passenger Experience.” APEX, April 7, 2016.
  9. Davies, Alex. “A Brilliant Double-Decker Armrest That Would Make Flying Less Hellish.” Wired, June 5, 2014.