COGNITIVE BIASES AND COMMUNICATION ERRORS

 

 COGNITIVE BIASES AND COMMUNICATION ERRORS

         

THE INCIDENT

          We were holding short of the parallel taxi track when I was nudged by the Captain to respond to the clearance given by ATC (Ground) to ‘clear to holding point RW28 and change over to tower’. I was a little startled as there was a call to that effect but it was (in my opinion) for some other aircraft. I expressed my reservation by questioning in a disapproving manner, “Was it for us?” He was sure and immediately called out to Navigator for confirmation to what he thought was the call. The Navigator promptly replied that he agrees with the Captain. I saw Captain almost putting parking brakes off and increasing power. I quickly carried out the ritual of call back by blurting out on RT that ‘we are moving to taxy holding and changing over to tower’. The Captain immediately started moving and I changed over to Tower. Soon I heard tower asking us to go back to the ground frequency where we were sternly asked the reason for moving without clearance. On our insistence that we had read back the clearance ATC reverted after going over the tape and told us that there was never any read back from our side regarding the assumed clearance. We apologized and the sortie went about uneventfully.

DYNAMICS OF COMMUNICATION

           Contrary to common understanding, during verbal communication, it is our brain and not ears which is the primary organ of hearing. Ears have a limited role in channeling sound waves to the brain where this information is processed, analyzed and interpreted by comparing it with the stored data of our lifelong learning and experiences.  The brain uses both verbal and non verbal cues to arrive at meaningful understanding of the message. In a typical verbal message almost 90% of the meaning comes through non verbal cues (body language 55% and tone 35%) while words convey just about 10% of the intended meaning. The brain is also susceptible to many limitations giving rise to errors in understanding the message. Like visual illusions the auditory illusions too are generated by our brain based on our beliefs and experiences. ‘You hear what you want to hear’ is much more common than our ego permits us to accept.

          An example of auditory illusion is the panic created on ‘back masking’ which gripped the US in 1980s.  Religious fundamentalist alleged that some of the popular rock groups were purposely inserting the satanic/evil/porn messages which were audible when the song was played in reverse mode (back masking). The proponents alleged that subconscious mind is able to decipher phonetic reversals thereby influencing the behavior of impressionable minds. They were able to make people to listen to such messages by playing the song in reverse. Beatles was one such group attacked. The phenomenon peaked in 1990 when the matter reached the court where it was dismissed. It was proved that there is simply no proof that subconscious mind can decipher phonetic reversals. It was shown by experiments that the brain searches patterns in noise/trash. A song when played backwards is merely incoherent noise but it offers possibilities for the brain to find some patterns especially if you have been told the lyrics to look out for. The brain thus is primed and tricked to hear those lyrics giving an impression that such a message actually exists.

 

AVIATION COMMUNICATION

          The aviation transactions are verbal, instantaneous and time sensitive. At the same time it has to be unambiguous and easily understood making it sort of oxymoron. All aviation communication is recorded and analyzed thread bare word for word in case of any mishap like a legal document. Compare these cryptic verbal messages shot out in rapid fire mode to standard legal documents which are voluminous, time consuming and repetitive to remove any ambiguity. Each word rolls around wrapped with coded information which could mean life and death for hundreds of people as was the case in the worst aviation accident at Tenerife on 27 Mar 77. “We are now at Takeoff” is perhaps the most disastrous misunderstood sentence in the aviation world spoken by KLM crew. The ATC felt that it conveyed that they were holding at takeoff point while the Captain felt that it conveyed that they were taking off. The error was complete when the ATC instructions “OK……Stand by for takeoff, I will call you” was squelched out by simultaneous transmission of other aircraft. Captain commenced takeoff roll with the loss of 583 lives. While the crew was blamed there were enough mitigating circumstances which forced the crew to assume fatalistically what they assumed. Aviation communication still relies, for confirmation, on primitive method called ‘read back’ and ‘hear back’.

          In the absence of visual contact the brain subconsciously starts relying on tone and the context along with words as happened in the flame out due to fuel starvation with Avianca Flight 52 in 19Jul 1989. The crew did not use the standard terminology for declaring the fuel emergency. They had however transmitted that they were ‘running low on fuel’. The controllers when confronted said that they could never decipher that the flight was in such a grave emergency as they heard no urgency or panic in the pilot’s communication indicating to them that all was normal.

          Verbal messages are transient and can be easily forgotten or misinterpreted. Listening is also hard work as it requires full attention to analyze the information and how it is going to affect the flight path. Mind is also prone to wandering affecting our listening capabilities and making us prone to errors of communication. Mistaking one aircrafts call sign for another is a perennial problem in aviation communication. Clearances for one aircraft but accepted by crew of another have led to altitude and heading deviations, accidents.

          English language has many homophones (similar sounding words) like ‘two’, ‘to’ and ‘four’, ‘for’. There was a fatal accident of Boeing 747 in Feb 1989 where the crew mistook the ATC clearance of descend two four zero (2400 feet) as descend to four zero (descend to 400 feet). Numbers too are confusing even if they are not similar sounding. The most commonly confused number which has earned a nick name also is the ‘ten eleven issue’. In a study it was found that ten eleven thousand pairing resulted in maximum altitude bursts. Almost all pilots report difficulty in interpreting messages with several zeroes especially with multiple instructions in one transmission.

COGNITIVE BIASES

           Cognitive biases are errors in thinking that influences our decision making process. These biases are deeply seeded in our mind and subconsciously affect our logical and rational thinking. We are generally not aware of them and fall easy prey. Even if we are aware it is very difficult to ignore them. However understanding about them will make us realize how vulnerable we are to making errors.   Now let us have a look at few of the many cognitive biases which wrongly influences our decision making through the taxying incident where we moved without any clearance.

          EXPECTATION BIAS      We were expecting clearance to move to holding point as this was the place at which we used to routinely get that clearance. Also there was no traffic till taxi holding point and it was just logical for the ATC to clear us further. Our brain which is always active gets further triggered when we are expecting something and would try and meet the expectation even if something closely resembling to that is heard.

  In this case the call was made by an aircraft having last two numbers similar to ours. Thus the Captain hears what he has tricked his mind to hear and brain willingly obliges. But he faces a problem in that his copilot who is in fact in charge of the RT natter doesn’t seem to agree with the Captain. The prospect of getting late and other multiple concerns is already there and his copilot is making it worse. He promptly throws the gauntlet to the Navigator by asking him if he too have heard what he has heard. He is now succumbing to the confirmation bias.

          CONFIMATION BIAS is the tendency of an individual to look or seek for selective information that supports/aligns to his understanding/interpretation/analysis of the situation and ignore anything that is contrary to that belief. Here the Captain has made a judgment and is now seeking information (selective) that aligns with that. Unknowingly he is pushing the navigator to yet another bias called authority bias.

          AUTHORITY BIAS is the tendency to attribute greater accuracy to the opinion of an authority figure. In various psychological experiments it has been shown that whenever there are conflicting views people tend to side with the person holding higher authority. It’s fairly common in deeply hierarchical culture like Military to avoid countering the top man. In this scenario the Captain was the authority figure in all terms like seniority, experience and appointment. Was it possible for the navigator to say that he was not sure when asked his views? Not likely as another bias called conformity bias comes into play. CONFORMITY BIAS is the innate tendency for humans to conform to people or group. Here the Navigator subconsciously needs to conform to one or the other. Now we see multiple biases supporting each other. The Navigator falls to authority bias and conformity bias whereas the Captain who is already trapped under expectancy bias gets selective information which confirms his expectations. The captain has also trapped the navigator subconsciously into what is called framing effect.

          FRAMING BIAS is a cognitive bias where the question is given a twist to elicit a preconceived reply. It can be intentional or subconscious and can play a significant influence on the answer. Note the extract of the speech of George W Bush made after twin tower attack “Every nation in every religion, now has a decision to make. Either you are with us, or you are with the terrorists.” The Captains question conveyed this bias when he said ‘Nav, I heard that we have been cleared to move up and change over to tower’. Instead he could have been more discreet in asking like ‘what was the call Nav?’ There is yet another bias which probably made the Captain to interpret the message in a manner in which he did it. And it is called filling in bias

          FILLING IN BIAS  It is relatively easy to trick the brain to hear a nonexistent sound or message especially when he is in a state of high expectation. The brain takes a mental short cut (Heuristic) and quickly fills in the details in conformity with his expectation. So it is possible that the Captain’s brain had inserted the call sign into the message which matched with his expectation. Research has shown that under high expectation mode the brains auditory cortex is activated in the same way as when you are actually hearing.

CONCLUSION

        Communication has been cited as a major factor in almost all accidents. Cicero was commenting scientifically about human nature when he said “To err is human”.  It’s a fact that errors cannot be eliminated in spite of any amount of training or information. The aim, instead, should be to reduce the chances of making mistakes and consequences less severe. Understanding, accepting and discussing our limitations especially the cognitive biases is bound to produce positive results in error management.

PN:-On discussing the issue after the trip and listening to the tape we realized that while transmitting to the ATC I had not put the LISTEN/RADIO button to RADIO and hence my read back was never heard as it was never transmitted. The ATC also clarified that they wanted to send its vehicle to the taxi holding position to pick up a dead bird close to the taxi holding position which was attracting other birds through the route which we blocked by erroneously taxiing out.