A few years ago, several dozen young men gathered on the steps of the courthouse in Baraboo, Wisconsin, to take pictures before their high-school prom. It is not clear what was going through each of their heads—though one could guess—when most of them extended their right arms, mimicking the Nazi salute as a parent snapped a picture. The students dropped their arms and went to prom. The head of the Baraboo School District issued a public apology and condemned the photograph. https://www.jsonline.com/story/news/education/2018/11/14/nazi-salute-photo-baraboo-school-chief-issues-apology/2006409002/ Two years before the picture was taken, students filed 12 harassment complaints with the Baraboo district during the 2016-2017 school year, 11 of which were based on the victims' race. Keegan Kyle and Eric Litke, Before Nazi salute picture, Baraboo schools saw a rise in racial complaints, Appleton Post-Crescent Nov. 20, 2018, https://www.postcrescent.com/story/news/2018/11/20/before-nazi-salute-picture-baraboo-schools-racial-complaints-rise/2016640002/
Despite the racially based harassment complaints, white students nonetheless stated that they had not noticed any problem with the culture at the school. White students also expressed surprise and confusion about why the picture was taken in the first place. Another white student excused the conduct saying while the gesture was upsetting it was just a joke. Susan Endres and Ben Bromley, Parents address school board as Nazi salutes in Baraboo High School prom photo spark outrage online Baraboo News Republic, WISC NEWS Nov. 13, 2018, https://www.wiscnews.com/baraboonewsrepublic/news/local/parents-address-school-board-as-nazi-salutes-in-baraboo-high-school-prom-photo-spark-outrage/article_3224ea4a-7423-5fc1-b2ca-20159f7129e5.html Various parents suggested education would be the answer to help students understand the gravity of their actions and the symbolism in which they partook. Id.
As the Baraboo parent suggested, we need to educate ourselves and make ourselves aware of our hidden biases that we have so that we recognize them and how they affect our thinking. Just as the white students expressed surprise and confusion about the picture showing fellow classmates doing a Nazi salute, we may be surprised by our own hidden biases in this case. If you are curious about your own biases, test yourself for hidden biases at the Implicit Association Test. https://implicit.harvard.edu/implicit/takeatest.html The test measures racial prejudices that we cannot consciously control. I have taken it three times now. My hidden bias, while present, has come in significantly below the average for white people like me.
IMPLICIT BIAS
People are not born with hidden biases or racial prejudices. We may never even have been “taught” them. Rather, prejudice draws on many of the same tools that help our minds figure out what is good and what is bad. In evolutionary terms, it is efficient to quickly classify a grizzly bear as “dangerous.” The trouble comes when the brain uses similar processes to form negative views about groups of people. As Justice Brennan explained, “racial bias inclines one to disbelieve and disfavor the object of the prejudice, and it is similarly incontestable that subconscious, as well as express, racial fears and hatred operate to deny fairness to the person despised.” Turner v. Murray, 476 U.S. 28, 42 (1986) (Brennan J., dissenting).
Our tendency to link individuals to the stereotypes associated with their group(s) is automatic and occurs outside of conscious awareness. These are “blink responses”; they reflect our “thinking without thinking.” Implicit bias is “an automatic and unconscious process, (and) people who engage in this unthinking discrimination are not aware of the fact that they do it.” Implicit biases can manifest even in people who, at the conscious level, reject prejudice and stereotyping. Greenwald, A. G., Mcghee, D. E., & Schwartz, J. L. K. (1998). Measuring Individual Differences in Implicit Cognition: The Implicit Association Test. Journal of Personality and Social Psychology, 74(6), 1464–80 (p. 1474), https://www.isu.edu/media/libraries/aaeo/drc/brown-bag-resources/Measuring-Individual-Differences-in-Implicit-Cognition---The-IAT---Greenwald-et-al.pdf;
Understanding implicit bias for police officers is recognizing that “officers might have biases that influence their behavior, judgments, and decisions, even if they are not explicitly or overtly biased against a particular group of people.” Renee J. Mitchell and Lois James, “Addressing the Elephant in the Room: The Need to Evaluate Implicit Bias Training Effectiveness for Improving Fairness in Police Officer Decision-Making,” Police Chief Online, November 28, 2018, https://www.policechiefmagazine.org/addressing-the-elephant-in-the-room/ “Police officers are likely to be just as susceptible to implicit bias as any other professional group—perhaps more so, given the nature of their work, which often focuses on negative aspects of human behavior.” Id.
Police Chief Magazine, the publication for the International Association of Chiefs of Police, has stated:
Perhaps the most salient example of implicit bias among police comes from widespread allegations of racially motivated policing. Cases in which police officers shoot unarmed black citizens typically result in public outcry, with the belief that officers were driven by racial bias. Officers, on the other hand, tend to assert that they were, in fact, responding to threat cues that they perceived. Interestingly, both groups might be correct. An illustrative example comes from George Fachner and Steven Carter’s threat perception failures (TPF). These researchers showed that implicit bias can influence an officer’s decision to shoot or not to shoot, by influencing the officer’s perception of reality. In this case, an officer incorrectly perceives that the suspect poses a deadly threat, due to the misperception of an object (such as a cellphone) or an action (such as reaching for a cellphone). When these researchers analyzed officer-involved shootings by the Philadelphia, Pennsylvania, Police Department (PPD), they found that TPF more frequently explained the shootings of unarmed African Americans compared to unarmed whites, speculating that officers may be subconsciously “on guard” with African American suspects. Renee J. Mitchell and Lois James, “Addressing the Elephant in the Room: The Need to Evaluate Implicit Bias Training Effectiveness for Improving Fairness in Police Officer Decision-Making,” Police Chief Online, supra. See, George Fachner and Steven Carter, COLLABORATIVE REFORM INITIATIVE An Assessment of Deadly Force in the Philadelphia Police Department (Office of Community Oriented Policing Services, U.S. Department of Justice 2015), https://www.phillypolice.com/assets/directives/cops-w0753-pub.pdf
Various studies have examined the Black-crime implicit bias. The studies found that subjects shot an armed male more quickly if he was Black than if he was White. Conversely, they more quickly decided not to shoot an unarmed White than an unarmed Black. The most common errors were shooting an unarmed Black man and not shooting an armed White man. L.A. Fridel, The Science of Implicit Bias and Implications for Policing, in Producing Bias-Free Policing A Science-Based Approach, Chap. 2, p. 7-30 (Springer Briefs in Translational Criminology 2017), https://www.springer.com/gp/book/9783319331737 Black suspects are more than twice as likely to be killed by police than are persons of other racial or ethnic groups. Fagan and Campbell, Race and reasonableness in police killings, 100 Boston Univ. L. Rev. 951 (2020), https://scholarship.law.columbia.edu/cgi/viewcontent.cgi?article=3660&context=faculty_scholarship. Individuals misidentified tools as guns more often when primed with a Black face than with a White face. Payne, Prejudice and perception: The role of automatic and controlled processes in misperceiving a weapon. Journal of Personality and Social Psychology, 81(2), 181–192 (2001), http://web.missouri.edu/~segerti/capstone/PayneBias.pdf.
FBI Director James Comey encouraged police departments to confront their own implicit biases, “Much research points to the widespread existence of unconscious bias. Many people in our white-majority culture have unconscious racial biases and react differently to a white face than a black face.” Director James B. Comey Federal Bureau of Investigation, "Hard Truths: Law Enforcement and Race" Georgetown University Washington, D.C. February 12, 2015, official transcript, https://www.fbi.gov/news/speeches/hard-truths-law-enforcement-and-race
EFFECTS ON THE INDIVIDUAL POLICE OFFICER WHEN CONFRONTED WITH A USE OF FORCE SITUATION
The dangers of a police officer shooting to bystanders is known. When police fired 16 times at an armed man, they hit nine bystanders and left 10 bullet holes in the suspect. This data shows what any police officer who has ever been involved in a shooting can tell you–firing accurately in a stressful situation is extremely hard. Amanda Ripley, Your Brain in a Shootout: Guns, Fear and Flawed Instincts, Time January 16, 2013, https://swampland.time.com/2013/01/16/your-brain-in-a-shootout-guns-fear-and-flawed-instincts/ This is true whether the officer is an experienced officer or officers with minimal experience. Lewinski et al., The real risks during deadly police shootouts: accuracy of the naive shooter, 17 Intl. Jrl. of Police Science & Mgmnt 117 (2015), https://pdf4pro.com/view/the-real-risks-during-deadly-police-shootouts-22ead5.html
In most cases, officers involved in shootings experience a kaleidoscope of sensory distortions including tunnel vision and a loss of hearing. Afterward, they are sometimes surprised to learn that they have fired their weapons at all. Rostker, Hanser, Hix, Jensen, Morral, Ridgeway, Schell, Evaluation of the New York City Police Department Firearm Training and Firearm-Discharge Review Process (RAND Center on Quality Policing 2008), https://www.rand.org/content/dam/rand/pubs/monographs/2008/RAND_MG717.pdf
Under sudden attack, the brain does not work the way we think it will. As happens for most people in life-or-death situations, an officer’s brain manipulate’s his perception of time, slowing down the motion. Id. For instance, one experienced officer in the middle of a gunfight raised his hands to shoot his weapon at an attacker only to realize he had dropped his weapon. Id. Without being aware of it, the officer had dropped his gun in the hallway when he reached over to help another wounded officer. In moments of extreme stress, the brain does not allow for contemplation; it does not process new information the way it normally does. The more advanced parts of the brain that handle decisionmaking go off-line, unable to intervene until the immediate fear has diminished. Id. “Race stereotypes can lead people to claim to see a weapon where there is none. Split-second decisions magnify the bias by limiting people’s ability to control responses. Such a bias could have important consequences for decision making by police officers and other authorities interacting with racial minorities. The bias requires no intentional racial animus, occurring even for those who are actively trying to avoid it.” Payne, Weapon Bias: Split-Second Decisions and Unintended Stereotyping, 15 Current Directions in Psychological Science 287 (2006), https://journals.sagepub.com/doi/pdf/10.1111/j.1467-8721.2006.00454.x
Racial bias can influence the “gut feelings” and conclusions about the amount force police perceive is needed in a situation. Awareness of these biases will help officers, like anyone else, fight them. See, Anthony Greenwald & Linda Krieger, Implicit Bias: Scientific Foundations, 94 Calif. L. Rev. 945, 948-51 (2006), https://pdfs.semanticscholar.org/c7b0/f3376d8e153cd7725de479447aa4c113ec8b.pdf?
_ga=2.256171468.639383428.1594653929-1128881295.1594653929 Research suggests that once we understand the psychological pathways that lead to prejudice, we just might be able to train our brains to go in the opposite direction. Janice Gassam Asare, Does Unconscious Bias Training Really Work? Forbes (Oct 29, 2018) ("The first step towards impacting unconscious bias is awareness.") https://www.forbes.com/sites/janicegassam/2018/10/29/does-unconscious-bias-training-really-work/#4141efb0b8a2
the Wisconsin Office of Justice Assistance, a division of the Wisconsin Department of Administration, has stated without qualification that “[r]acial disparities permeate the entire criminal justice continuum, in the number of arrests, cases charged, sentences and probation and parole revocations.” Wisconsin Office of Justice Assistance, Racial Disparities, http://oja.wi.gov/section.asp?linkid=1344&locid=97. Since racial disparities permeate the entire criminal justice continuum, it would be foolish to argue racial disparities do not extend to how police use force: “Black men tend to be stereotyped as threatening and, as a result, may be disproportionately targeted by police even when unarmed.” Wilson, J. P., Hugenberg, K., & Rule, N. O. Racial bias in judgments of physical size and formidability: From size to threat. Journal of Personality and Social Psychology, 113(1), 59–80 (2017), https://psycnet.apa.org/record/2017-11085-001; Frank Edwards, Hedwig Lee, and Michael Esposito, Risk of being killed by police use of force in the United States by age, race–ethnicity, and sex PNAS (2019) (“people of color face a higher likelihood of being killed by police than do white men and women.”) https://www.pnas.org/content/pnas/116/34/16793.full.pdf; Hehman, Flake, and Calanchini, Disproportionate Use of Lethal Force in Policing Is Associated With Regional Racial Biases of Residents, Social Psychological and Personality Science Volume 9 Issue 4, May 2018 (only the implicit racial prejudices and stereotypes of White residents, beyond major demographic covariates, are associated with disproportionally more use of lethal force with Blacks relative to regional base rates of Blacks in the population.) https://journals.sagepub.com/doi/pdf/10.1177/1948550617711229; Using data on over 2 million police stops in New York City from 2007 to 2014, findings show that Black and White civilians experience fundamentally different interactions with police. Black civilians are particularly more likely to experience potential lethal force when police uncover criminal activity and this disparity is greatest for black youth compared to white youth. Rory Kramer and Brianna Remster, Stop, Frisk, and Assault? Racial Disparities in Police Use of Force During Investigatory Stops, Law and Society Review Vol. 52, Issue 4 Dec. 2018, p. 960-93, https://onlinelibrary.wiley.com/doi/abs/10.1111/lasr.12366.
Despite the racially based harassment complaints, white students nonetheless stated that they had not noticed any problem with the culture at the school. White students also expressed surprise and confusion about why the picture was taken in the first place. Another white student excused the conduct saying while the gesture was upsetting it was just a joke. Susan Endres and Ben Bromley, Parents address school board as Nazi salutes in Baraboo High School prom photo spark outrage online Baraboo News Republic, WISC NEWS Nov. 13, 2018, https://www.wiscnews.com/baraboonewsrepublic/news/local/parents-address-school-board-as-nazi-salutes-in-baraboo-high-school-prom-photo-spark-outrage/article_3224ea4a-7423-5fc1-b2ca-20159f7129e5.html Various parents suggested education would be the answer to help students understand the gravity of their actions and the symbolism in which they partook. Id.
As the Baraboo parent suggested, we need to educate ourselves and make ourselves aware of our hidden biases that we have so that we recognize them and how they affect our thinking. Just as the white students expressed surprise and confusion about the picture showing fellow classmates doing a Nazi salute, we may be surprised by our own hidden biases in this case. If you are curious about your own biases, test yourself for hidden biases at the Implicit Association Test. https://implicit.harvard.edu/implicit/takeatest.html The test measures racial prejudices that we cannot consciously control. I have taken it three times now. My hidden bias, while present, has come in significantly below the average for white people like me.
IMPLICIT BIAS
People are not born with hidden biases or racial prejudices. We may never even have been “taught” them. Rather, prejudice draws on many of the same tools that help our minds figure out what is good and what is bad. In evolutionary terms, it is efficient to quickly classify a grizzly bear as “dangerous.” The trouble comes when the brain uses similar processes to form negative views about groups of people. As Justice Brennan explained, “racial bias inclines one to disbelieve and disfavor the object of the prejudice, and it is similarly incontestable that subconscious, as well as express, racial fears and hatred operate to deny fairness to the person despised.” Turner v. Murray, 476 U.S. 28, 42 (1986) (Brennan J., dissenting).
Our tendency to link individuals to the stereotypes associated with their group(s) is automatic and occurs outside of conscious awareness. These are “blink responses”; they reflect our “thinking without thinking.” Implicit bias is “an automatic and unconscious process, (and) people who engage in this unthinking discrimination are not aware of the fact that they do it.” Implicit biases can manifest even in people who, at the conscious level, reject prejudice and stereotyping. Greenwald, A. G., Mcghee, D. E., & Schwartz, J. L. K. (1998). Measuring Individual Differences in Implicit Cognition: The Implicit Association Test. Journal of Personality and Social Psychology, 74(6), 1464–80 (p. 1474), https://www.isu.edu/media/libraries/aaeo/drc/brown-bag-resources/Measuring-Individual-Differences-in-Implicit-Cognition---The-IAT---Greenwald-et-al.pdf;
Understanding implicit bias for police officers is recognizing that “officers might have biases that influence their behavior, judgments, and decisions, even if they are not explicitly or overtly biased against a particular group of people.” Renee J. Mitchell and Lois James, “Addressing the Elephant in the Room: The Need to Evaluate Implicit Bias Training Effectiveness for Improving Fairness in Police Officer Decision-Making,” Police Chief Online, November 28, 2018, https://www.policechiefmagazine.org/addressing-the-elephant-in-the-room/ “Police officers are likely to be just as susceptible to implicit bias as any other professional group—perhaps more so, given the nature of their work, which often focuses on negative aspects of human behavior.” Id.
Police Chief Magazine, the publication for the International Association of Chiefs of Police, has stated:
Perhaps the most salient example of implicit bias among police comes from widespread allegations of racially motivated policing. Cases in which police officers shoot unarmed black citizens typically result in public outcry, with the belief that officers were driven by racial bias. Officers, on the other hand, tend to assert that they were, in fact, responding to threat cues that they perceived. Interestingly, both groups might be correct. An illustrative example comes from George Fachner and Steven Carter’s threat perception failures (TPF). These researchers showed that implicit bias can influence an officer’s decision to shoot or not to shoot, by influencing the officer’s perception of reality. In this case, an officer incorrectly perceives that the suspect poses a deadly threat, due to the misperception of an object (such as a cellphone) or an action (such as reaching for a cellphone). When these researchers analyzed officer-involved shootings by the Philadelphia, Pennsylvania, Police Department (PPD), they found that TPF more frequently explained the shootings of unarmed African Americans compared to unarmed whites, speculating that officers may be subconsciously “on guard” with African American suspects. Renee J. Mitchell and Lois James, “Addressing the Elephant in the Room: The Need to Evaluate Implicit Bias Training Effectiveness for Improving Fairness in Police Officer Decision-Making,” Police Chief Online, supra. See, George Fachner and Steven Carter, COLLABORATIVE REFORM INITIATIVE An Assessment of Deadly Force in the Philadelphia Police Department (Office of Community Oriented Policing Services, U.S. Department of Justice 2015), https://www.phillypolice.com/assets/directives/cops-w0753-pub.pdf
Various studies have examined the Black-crime implicit bias. The studies found that subjects shot an armed male more quickly if he was Black than if he was White. Conversely, they more quickly decided not to shoot an unarmed White than an unarmed Black. The most common errors were shooting an unarmed Black man and not shooting an armed White man. L.A. Fridel, The Science of Implicit Bias and Implications for Policing, in Producing Bias-Free Policing A Science-Based Approach, Chap. 2, p. 7-30 (Springer Briefs in Translational Criminology 2017), https://www.springer.com/gp/book/9783319331737 Black suspects are more than twice as likely to be killed by police than are persons of other racial or ethnic groups. Fagan and Campbell, Race and reasonableness in police killings, 100 Boston Univ. L. Rev. 951 (2020), https://scholarship.law.columbia.edu/cgi/viewcontent.cgi?article=3660&context=faculty_scholarship. Individuals misidentified tools as guns more often when primed with a Black face than with a White face. Payne, Prejudice and perception: The role of automatic and controlled processes in misperceiving a weapon. Journal of Personality and Social Psychology, 81(2), 181–192 (2001), http://web.missouri.edu/~segerti/capstone/PayneBias.pdf.
FBI Director James Comey encouraged police departments to confront their own implicit biases, “Much research points to the widespread existence of unconscious bias. Many people in our white-majority culture have unconscious racial biases and react differently to a white face than a black face.” Director James B. Comey Federal Bureau of Investigation, "Hard Truths: Law Enforcement and Race" Georgetown University Washington, D.C. February 12, 2015, official transcript, https://www.fbi.gov/news/speeches/hard-truths-law-enforcement-and-race
EFFECTS ON THE INDIVIDUAL POLICE OFFICER WHEN CONFRONTED WITH A USE OF FORCE SITUATION
The dangers of a police officer shooting to bystanders is known. When police fired 16 times at an armed man, they hit nine bystanders and left 10 bullet holes in the suspect. This data shows what any police officer who has ever been involved in a shooting can tell you–firing accurately in a stressful situation is extremely hard. Amanda Ripley, Your Brain in a Shootout: Guns, Fear and Flawed Instincts, Time January 16, 2013, https://swampland.time.com/2013/01/16/your-brain-in-a-shootout-guns-fear-and-flawed-instincts/ This is true whether the officer is an experienced officer or officers with minimal experience. Lewinski et al., The real risks during deadly police shootouts: accuracy of the naive shooter, 17 Intl. Jrl. of Police Science & Mgmnt 117 (2015), https://pdf4pro.com/view/the-real-risks-during-deadly-police-shootouts-22ead5.html
In most cases, officers involved in shootings experience a kaleidoscope of sensory distortions including tunnel vision and a loss of hearing. Afterward, they are sometimes surprised to learn that they have fired their weapons at all. Rostker, Hanser, Hix, Jensen, Morral, Ridgeway, Schell, Evaluation of the New York City Police Department Firearm Training and Firearm-Discharge Review Process (RAND Center on Quality Policing 2008), https://www.rand.org/content/dam/rand/pubs/monographs/2008/RAND_MG717.pdf
Under sudden attack, the brain does not work the way we think it will. As happens for most people in life-or-death situations, an officer’s brain manipulate’s his perception of time, slowing down the motion. Id. For instance, one experienced officer in the middle of a gunfight raised his hands to shoot his weapon at an attacker only to realize he had dropped his weapon. Id. Without being aware of it, the officer had dropped his gun in the hallway when he reached over to help another wounded officer. In moments of extreme stress, the brain does not allow for contemplation; it does not process new information the way it normally does. The more advanced parts of the brain that handle decisionmaking go off-line, unable to intervene until the immediate fear has diminished. Id. “Race stereotypes can lead people to claim to see a weapon where there is none. Split-second decisions magnify the bias by limiting people’s ability to control responses. Such a bias could have important consequences for decision making by police officers and other authorities interacting with racial minorities. The bias requires no intentional racial animus, occurring even for those who are actively trying to avoid it.” Payne, Weapon Bias: Split-Second Decisions and Unintended Stereotyping, 15 Current Directions in Psychological Science 287 (2006), https://journals.sagepub.com/doi/pdf/10.1111/j.1467-8721.2006.00454.x
Racial bias can influence the “gut feelings” and conclusions about the amount force police perceive is needed in a situation. Awareness of these biases will help officers, like anyone else, fight them. See, Anthony Greenwald & Linda Krieger, Implicit Bias: Scientific Foundations, 94 Calif. L. Rev. 945, 948-51 (2006), https://pdfs.semanticscholar.org/c7b0/f3376d8e153cd7725de479447aa4c113ec8b.pdf?
_ga=2.256171468.639383428.1594653929-1128881295.1594653929 Research suggests that once we understand the psychological pathways that lead to prejudice, we just might be able to train our brains to go in the opposite direction. Janice Gassam Asare, Does Unconscious Bias Training Really Work? Forbes (Oct 29, 2018) ("The first step towards impacting unconscious bias is awareness.") https://www.forbes.com/sites/janicegassam/2018/10/29/does-unconscious-bias-training-really-work/#4141efb0b8a2
the Wisconsin Office of Justice Assistance, a division of the Wisconsin Department of Administration, has stated without qualification that “[r]acial disparities permeate the entire criminal justice continuum, in the number of arrests, cases charged, sentences and probation and parole revocations.” Wisconsin Office of Justice Assistance, Racial Disparities, http://oja.wi.gov/section.asp?linkid=1344&locid=97. Since racial disparities permeate the entire criminal justice continuum, it would be foolish to argue racial disparities do not extend to how police use force: “Black men tend to be stereotyped as threatening and, as a result, may be disproportionately targeted by police even when unarmed.” Wilson, J. P., Hugenberg, K., & Rule, N. O. Racial bias in judgments of physical size and formidability: From size to threat. Journal of Personality and Social Psychology, 113(1), 59–80 (2017), https://psycnet.apa.org/record/2017-11085-001; Frank Edwards, Hedwig Lee, and Michael Esposito, Risk of being killed by police use of force in the United States by age, race–ethnicity, and sex PNAS (2019) (“people of color face a higher likelihood of being killed by police than do white men and women.”) https://www.pnas.org/content/pnas/116/34/16793.full.pdf; Hehman, Flake, and Calanchini, Disproportionate Use of Lethal Force in Policing Is Associated With Regional Racial Biases of Residents, Social Psychological and Personality Science Volume 9 Issue 4, May 2018 (only the implicit racial prejudices and stereotypes of White residents, beyond major demographic covariates, are associated with disproportionally more use of lethal force with Blacks relative to regional base rates of Blacks in the population.) https://journals.sagepub.com/doi/pdf/10.1177/1948550617711229; Using data on over 2 million police stops in New York City from 2007 to 2014, findings show that Black and White civilians experience fundamentally different interactions with police. Black civilians are particularly more likely to experience potential lethal force when police uncover criminal activity and this disparity is greatest for black youth compared to white youth. Rory Kramer and Brianna Remster, Stop, Frisk, and Assault? Racial Disparities in Police Use of Force During Investigatory Stops, Law and Society Review Vol. 52, Issue 4 Dec. 2018, p. 960-93, https://onlinelibrary.wiley.com/doi/abs/10.1111/lasr.12366.
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