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Cognitive Biases

  • 1.  Cognitive Biases

    Posted 02-08-2021 02:26 PM

    This is a fascinating and I think fun topic and I am hoping others will weigh in with their own experience, particularly as seen or experienced in engineering practice. I first became aware of this topic in the early 1990 when first exposed to the concept of decision quality (a future topic) and in particular the disabling role of anchoring.

    As  a brief background, the notion of cognitive biases was first identified by Amos Tversky and Daniel Kahneman in work published in the early 1970s. The role cognitive biases play in everyday life has now become far ranging from Behavioral Economics to baseball's Sabermetrics. They are also also making their into engineering, e.g., February's free paper: Value of Information on Resilience Decision-Making in Repeated Disaster Environments.

    Examples of cognitive biases - also referred to as heuristics - include:

    • Anchoring - Why we tend to rely heavily upon the first piece of information we receive?
    • Availability - Why do we tend to think that things that happened recently are more likely to happen again?
    • IKEA effect - Why do we place disproportionately high value on things we helped to create?
    • Representativeness  - Why do we use similarity to gauge statistical probability?

    Finally, if you read and liked Michael Lewis' book Moneyball I highly recommend his follow up book the Undoing Project. The  provides the why behind former. There's also a nice article from the New Yorker The Two Friends Who Changed How We Think About How We Think that serves as a great intro to the overall subject of cognitive biases.

    Mitch Winkler P.E., M.ASCE
    Houston, TX

  • 2.  RE: Cognitive Biases

    Posted 02-15-2021 06:39 PM
    I'm really interested to see if anyone has some examples of this in their engineering experience.

    One way I have seen it is in developers or other clients having an extremely difficult time accepting changes from what they were initially told. (For example, if unknown geotechnical conditions are discovered on site, they may want a second opinion even though this information is being delivered by the same professional that delivered the initial analysis based on the borings.) 

    For this reason, I think it is critical that we, as engineers, are very careful how we present initial information since that first piece of information is often held so tightly as fact.

    Heidi Wallace EI, P.E., M.ASCE
    Tulsa OK

  • 3.  RE: Cognitive Biases

    Posted 02-22-2021 09:16 AM
    Part of your job is salesmanship to prepare the client for potential setbacks beyond your control. By nature, developers are Type A and in a hurry to complete a project. Setbacks bug them and you are the easiest person to vent on. That goes with the territory. With time you learn good clients from bad clients.

    Gordon England P.E., D.WRE(Ret.), M.ASCE
    Cocoa Beach FL

  • 4.  RE: Cognitive Biases

    Posted 02-22-2021 10:51 AM
    I can tell Gordon has been doing this for a while and I appreciated his comment " Setbacks bug them". I've literally told my design team on more than one occasion "I'm paying for your time and expertise, right now its just time and I need you to listen to me vent for a moment."

    For our younger engineers.....Yes, setbacks bug developers...like a lot!!! LOL

    This is because development projects are a lot like gambling.  You see....the goal of a development project is to make a profit on an investment. So what are the choices one has for a profit from an investment. A developer could put money in the stock market and leave it there, or could take their money to Vegas and put it all on red. But they choose to develop real estate for the illusion of control and because they take pride in the works and/or genuinely enjoy what they do. We hire experts to help navigate the rough waters. We get frustrated when our captain's run the ship through rough seas. We know they don't control the seas but we hope we they are good enough to see it coming and navigate appropriatly.

    Jesse Kamm PhD, PMP, A.M.ASCE
    Senior Vice President of Construction Management

  • 5.  RE: Cognitive Biases

    Posted 02-18-2021 10:04 AM
    I like what Heidi said. I definitely have seen some examples of anchoring bias as well in my own line of work. One of the things we do with hydrologic models is to re-calibrate them as more data becomes available to us. It is not uncommon for clients to be surprised and confused when this additional information changes some of the flow values that come from these updated models, even when the results are more favorable to them than they were initially.

    Christopher Seigel P.E., M.ASCE
    Civil Engineer

  • 6.  RE: Cognitive Biases

    Posted 02-18-2021 01:19 PM
      |   view attached
    I agree that engineers should learn more about cognitive biases.  A good place to start is "Thinking, Fast and Slow" by Daniel Kahneman, one of the two friends referenced in the original post.   The SEI Engineering Philosophy Committee (of which I am presently the chair) held a session at the 2013 Structures Congress where I presented a paper on this subject.  I have attached it for those who might be interested.  

    Bill Bulleit, PhD, PE
    Michigan Tech

    William Bulleit P.E., M.ASCE
    Michigan Tech University
    Houghton MI wmbullei@...


    Struc13TooFast.pdf   3.85 MB 1 version

  • 7.  RE: Cognitive Biases

    Posted 02-23-2021 05:49 PM
    Hi Bill, thanks for sharing your paper! I downloaded and look forward to reading. Please give my regards to Professor Mattila. We were classmates at Cornell.

    Mitch Winkler P.E., M.ASCE
    Houston, TX

  • 8.  RE: Cognitive Biases

    Posted 02-18-2021 01:20 PM
    Heidi and Christopher - these are great real life examples of anchoring and thanks for sharing. I hope others will continue to add their own experiences. 

    One i will share in the meanwhile is the IKEA effect. During my career i worked with many individuals who were always quick to knock the ideas of others. At the time, we referred to this as the not invented here syndrome. Upon reflection, I think this was a manifestation of the IKEA effect. If they did not think of the idea, it was not worthy. This was tantamount to disproportionately placing a higher value on something of their own creation. 


    Mitch Winkler P.E., M.ASCE
    Houston, TX

  • 9.  RE: Cognitive Biases

    Posted 02-19-2021 02:41 PM
    How much does our professional cognitive bias influence our practise? Let's take transportation design as an example: We make traffic and population growth projections, often linearly extrapolating a current short-term trend decades into the future. Time and again, after funding massively expensive projects that severely alter the landscape and character a city, we look back and realise that that growth just never materialised. We widen streets and roads with the expectation their expansion is needed now, but after spending millions of dollars of the municipal budget, realise that the growth never came. Or worse, it does come, but decades after we built the infrastructure such that in its first lifecycle it didn't get used.

    As a profession, I think we're incredibly biased, especially since we're supposed to be the "experts." But engineering, more often than not, is rule-of-thumb and best practise, not scientific law. (I would argue that the problem solving required to find solutions to unique and interesting engineering situations is one of the aspects that draws us to the field, so this fact is not a negative, but helps keep us interested and engaged in the profession.) Too often, instead of approaching a situation humbly in search of a solution, we turn to a manual and treat it as the Bible, even though most manuals explicitly state that they are just guidelines, not gospel.

    Joel Dixon P.E., M.ASCE
    Oklahoma City OK

  • 10.  RE: Cognitive Biases

    Posted 03-02-2021 09:01 AM
    Edited by Tirza Austin 03-02-2021 09:00 AM
    That's a good point, but I don't think I've ever been on a highway more than a year or two old that was that overdesigned - the traffic finds them.  An underused urban street can be made into a nice linear park.

    As a young engineer, I was working on a master sewer plan for a small city.  They were experiencing very rapid growth, but we were directed to design based on the zoning.  They had a lot of undeveloped land which had been zoned for fairly dense uses.  Based on zoning, they could support a population well over ten times the existing, but even at the rapid growth rate they were experiencing the population would not reach that level for fifty years, and at a more normal growth rate it would take centuries.  When I pointed that out to the planning director, he looked at me, mouth agape, for several seconds and then asked "So, you think we have too much residential zoning?"  My reply was that we should not be planning massive interceptor sewers to support a population that may never exist, but should plan for flexibility to support what was likely to happen during the life of the facilities we were planning.

    William Forbes MASCE, PE, ME, BCEE
    Senior Principal Engineer/Vice President of Engineering
    Forensic Analysis & Engineering Corporation
    Virginia Beach, Virginia

  • 11.  RE: Cognitive Biases

    Posted 03-02-2021 01:05 PM
    I beg to differ with Mr. Forbes. Rarely is infrastructure over designed. Smart planning looks 10-20 years in the future when it will be almost impossible to upgrade roads or sewers to catch up with growth. In the 80s-90s Austin tried to stop growth by freezing new roadways and not upgrading existing highways for a decade. The thought was that with no WWTP capacity and crowded roads, development would stay away. Development happened anyway with individual subdivision package plants etc. The roads filled with more cars. During rush hours the highways were shut down for hours. Austin has been playing catch up every since, not being able to buy land to widen highways or build new ones. They will never be able to plan 20 years into the future now. Their traffic is some of the worst in the country around the clock.
    It is more cost effective to overdesign now than to go back and tear up homes and roads in 20 years to catch up.

    Gordon England P.E., D.WRE(Ret.), M.ASCE
    Brevard County Storywater Dept.
    Stormwater Engineer

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