Over the past couple of weeks, three different planes have been diverted from their original flight plans because of unruly passengers. These disruptive individuals weren't threatening the safety of the other passengers, rather, they became outraged over personal space, causing enough commotion to remove them from the plane.

The in-flight confrontations

The first diversion occurred Aug. 24 on a United Airlines flight traveling from Newark, New Jersey, to Denver. Passenger James Beach used a gadget called the Knee Defender that prevents the seat in front from reclining. The woman in the seat in front of Beach became infuriated and the volatile confrontation began. The flight ended up being diverted to Chicago where the two passengers were removed.

On Aug. 27, a flight from Miami to Paris was diverted to Boston because passenger Edmund Alexandre became outraged when the passenger in front of him tried to recline her seat. Crew members tried to calm Alexandre, but the confrontation became physical and an air marshal had to handcuff Alexandre.

The third occurrence happened Sept. 1 on a flight from New York City to West Palm Beach, Florida. A passenger attempted to recline her seat, and the woman behind her started screaming and using inappropriate language. She insisted that the flight land.

The invasion of personal space

Each flight disruption was different, but the cause of the problems were all the same: an invasion of personal space. According to an article on Psych Central, individuals are most comfortable at 2 to 4 feet apart. Anything closer is considered an invasion of personal space, which causes anxiety.

On top of the invasion of personal space, there are many other factors that increase hostility and anxiety for airline passengers. Planes are full of strangers, making people less comfortable. Passengers can feel helpless — they can’t make the plane go faster, they can’t switch seats and they can’t chose who sits next to them. All these factors increase anxiety of passengers, increasing the odds of a hostile confrontation.

The Knee Defender

In response to the lack of personal space on planes, Ira Goldman, a former Capitol Hill staff member, created the Knee Defender in 2003. The Knee Defender is a plastic palm-size clip that attaches to a passenger's tray table, preventing the seat from reclining. For Goldman, this device would reduce his anxiety by securing his own space without fear of invasion. However, it has also caused a severe problem: Many passengers feel reclining the seat is a right that shouldn’t be taken away from them.

Airlines responded to the Knee Defender quickly after its release because the Federal Aviation Administration decided to leave the regulation of the device up to the individual airlines. Most major airlines, including United Airlines and Northwest Airlines, prohibited the use of the Knee Defender. So, Beach’s recent use of the device that caused the first plane diversion should never have occurred based on airline regulations, but it did happen.

After the recent in-flight problems, major airlines are reviewing company policies regarding personal space issues. Major airlines that do not have policies are considering banning the device, while budget carriers like Ryanair and Spirit Airlines have switched to nonreclining seats as a solution.

Airlines have the final decision regarding the device, but what do Americans think of the device? According to a Google Consumer Survey by Skift, 66 percent of Americans want devices like the Knee Defender to be prohibited. However, after looking closely at the demographics, the survey revealed that males are more accepting of the devices, and the rich and older Americans are more likely to be against such devices.

What caused the need for such devices?

Airlines are constantly trying to increase revenue and profits, and one way they have accomplished this goal is by increasing the number of seats on each plane. Reducing the space between rows allowed for more seats, in turn increasing revenue. The constantly decreasing space between seats as well as the decreasing size of the seats has caused issues throughout all airlines. Passengers are unhappy with the reduction of personal space.

According to an article on IndependentTraveler.com, "the ‘standard’ seat pitch has decreased almost industry-wide from 33-34 inches to more like 31 inches." Some smaller planes designed for short trips have even less room at 28 inches.

Overweight passengers affected

On top of minimal space between rows, the 17-inch-wide seats are barely wide enough to fit an average adult. How does the airplane seat compare to other public seats? According to The Wall Street Journal, a first-class seat on a Boeing 777 is 21 inches wide, a seat in a movie theater is 25 inches wide and an Amtrak Coach seat is 20.5 inches wide.

The width of the seats makes space within each row extremely cramped. How does this affect overweight and obese passengers? Many airlines have created policies to accommodate these passengers.

Southwest Airlines, for example, has a "customer of size" policy. According to the Southwest Airlines website, customers who are unable to fit between the armrests of the seat can purchase an additional seat. This will let the airline know of the circumstances and guarantee room for the passenger. Southwest Airlines will then refund the money for the second seat. Even though this is meant to satisfy all customers, many feel that this singles out certain individuals and can cause humiliation.

Southwest Airlines received a lot of publicity for the "customer of size" policy in the past. For example, in 2009, Emery Orto, a 350-pound man, was denied access to a flight because of his size even though he was prepared to prove he could fit within one seat. According to a Southwest Airlines spokeswoman, it was because of Orto’s irrational behavior; according to Orto, it was discrimination.

The recent plane diversions have triggered passengers and airlines to rethink personal space on planes. Should devices like the Knee Defender be banned? Should seats be able to recline? Should overweight passengers be forced to purchase additional seats? Should individuals be denied access to a flight because of weight? There is no right or wrong solution to the problem, but one thing is certain: Airlines need to address the issue and find a way to satisfy passengers, or conflicts like the recent plane diversions will continue.