Saturday, July 16, 2016

What Is Missing From The Divisiveness Debate?

Migratory routes of Homo heidelbergensis from East African origins (numbers are approximate years in past) - see attribution for reference.  Homo heidelbergensis is thought to be the common ancestor for Neanderthals, Denisovans, and modern humans - Homo sapiens.

The recent high profile incidents involving the shooting deaths of young black men and police officers and the associated news coverage and involvement by high profile celebrities and politicians has sparked a social activism, debate, and dialogue.  Like any complex issue, there are people who have opinions that mirror their political party lines, people who have their own opinions and they are not interested in changing them and people who are more open to a dialogue.  Practically all of the dialogue seems focused on high risk incidents that happen in a matter of seconds that involve deadly force.  I have seen some neuroscientific ponderings about how unconscious or implicit biases can affect those split second decisions.  I thought that was possible until I went to the web site and took the tests involving implicit bias.  There was not a single case where I could not predict the outcome ahead of time based on what I already know about myself.  To me it appeared that unconscious bias was not operating in the decision.  Since I am a white psychiatrist and not a police officer, I am not going to suggest specific solutions for police officers or the black community.  I do see a number of scientific dimensions that nobody or very few people are talking about so it is time to add my two cents:

1.  We are all from Africa -

Practically all of the debate centers on race.  There are statistical studies that show black drivers are stopped at higher rates than white drivers.  There are more white people killed by the police but as a proportion of the population black people are overrepresented.  The numbers are real and require serious analysis, but the larger picture is ignored.  That larger picture is that race is a social and cultural convention and not a scientific one.  On a scientific basis, everyone in the world - all human beings originated in East Africa about 200,000 years ago.  At some point, different races were described but at the time this genetic evidence was unknown.  The genetic evidence for racial and ethnic differences is still an area of active investigation.  Those studies illustrate the difference in skin color for example may come down to mutations in two genes (1, 2).  At the proteomic level, a recent study (3) looked at an analysis of interindividual variation in the total number of proteins that could be identified in cerebrospinal fluid (CSF) and urine and found considerable variation between individuals.  There was a 26% difference across 968 urinary proteins and a 18% difference for 512 CSF proteins.  Those numbers are very large compared with the difference between 1 or 2 skin proteins.

Although the total number of proteins identified in the human proteins is 10,500, estimate of the true size has varied from 10,000 to several billion (4) making the number of proteins responsible for skin color differences even less significant.  More skin specific information is available from the Human Protein Atlas.  Their analysis shows that there are 95 skin enriched genes and 412 genes with enhanced expression in the skin.  Only three of these genes MLANA, DCT, and TYR involve melanin synthesis or skin pigmentation.  Person to person variation on an arbitrary racial classification based on skin color is obscured by the expected genetic variation among members of the same race.

Further evidence is available to anyone by sending their DNA for analysis by the National Geographic Genographic Project.  You will receive a map of how your ancestors migrated from East Africa and information about marker that you share with other ethnic groups across the world.  The analysis will also include information about DNA that you share with ancient humans specifically Neanderthals and Denisovans.  The current project also estimates regional ancestry based on markers that appeared over time if migration from Africa occurred.  All of these science considerations should point to the fact that what we have generally considered to be racial boundaries may have political and cultural meaning to people - but there is no scientific meaning.  Every human being on the planet is descended from a small group of ancestors in East Africa.  Time to put the cultural and political stereotypes about race behind us.        

2.  Every person in the world has a unique conscious state -

One of the concepts that I am careful to mention whenever I am discussing aspects of psychiatric diagnosis is human consciousness.  From a neurobiological perspective the human brain has evolved to be a very efficient information processor.   Plasticity leads to experience dependent changes in the brain.  Experience can have a biasing effect of the general form that "my experience is everyone's experience" or "my experience is more valuable than anyone else's experience" or in the extreme case "my experience is the only one that counts."  Fortunately the human brain also has top-down controls like empathy, the ability to recognize that other unique conscious states exist, and the ability to correct its own erroneous biases.  Just the fact that every person on earth has a unique conscious state has significant ethical and moral implications for how one person interacts with another.  Those individual ethical imperatives are seriously watered down by political and legal limits that often target the lowest common denominator.    

3.  Anger has a predictable biasing effect -

Let me start off by saying that this paragraph is not meant to discount anyone's anger.  Anger is a universal human emotion, but the analysis of anger usually stops at the point of whether it is justified or not.  The analysis seldom looks at how anger biases subsequent decisions or how it might affect the initial encounter between the police and suspects.  Any student of social media can observe the very predictable polarizing arguments that occur following these incidents.  Partisans will frequently post arguments and counterarguments followed by statistics and counter statistics.  In many cases the arguments are rhetorical at at some level fallacious.  The dynamic driving these arguments is never mentioned and that dynamic is anger.  Anger has been studied by cognitive scientists and it functions to squarely focus blame on a specific person whether that is accurate or not.  This is as important for the police officer on the scene as it is for the secondary clashes between protesters, the public and the police.  When police officers confront a suspect and start swearing angrily at him/her to comply with their demands - that may be part of their training, it may be something that happens spontaneously, but in either case any real anger on the part of the officer implies that the subject has done something wrong and that the officer's decision-making capacity may be affected by his/her emotional state.  Emotions are critical in human decisions, but not all emotions result in a focus on another person as a source of wrongdoing.  

4.  Human reaction time is a limiting factor - 

The human nervous system takes time to process information.  There is surprisingly little public data available on how much time there is to make a decision to shoot an armed suspect.  The only study I could find (6) involved a simulation where an untrained armed suspect was either holding a handgun to his own head because he was allegedly suicidal or holding a handgun at his side when confronted by a police officer.  In the case where the suspect decides to fire a shot at the officer instead - it took an average of 380 msec.  Highly trained officers shot in 390 msec.  That translated to inexperienced suspects shooting first or tying the officers in 60% of the scenarios.  An interesting article in the literature also suggests that shooting errors in high threat situations persist even after weeks of practicing these scenarios (7).  For comparison, this web site allows for a determination of reaction time in a scenario that is completely free from distractions and noise - like anxiety and trying to determine if what the suspect is holding is really a firearm or not.  It is obvious that these decisions to fire by both officers and armed suspects are not like they are portrayed in television programs and films.  In real life there are no prolonged standoffs with officers and suspects pointing firearms at one another while they talk.    

5.  Human beings have a long history of solving difficult problems through violence and aggression -

One of the major lessons of human history is that lives matter only up to a point and if nobody agrees at that point - people will die.  In human history there are very few exceptions to that concept.  The best analysis of the situation that I have seen comes from anthropology (8) and the detailed study of modern and ancient warfare.  Several authors have written about the attractiveness of war to some of the participants - most prominent Chris Hodges (9).  The powerful combination of war and winning a conflict by force and being reinforced by the secondary aspects of camaraderie, teamwork, meaningfulness, and the political illusions of what an armed conflict can accomplish are all powerful incentives to avoid peace and conflict resolution.  The last time there was as serious peace movement in the USA it was largely a reaction to a prolonged and unnecessary war in Vietnam.  Since then there have been three unnecessary wars and no corresponding peace movements.

The war metaphor doesn't stop at the level of nations fighting nations.  At the next level it is always local governments and police departments fighting drug dealers, gangs, terrorists and various criminals.  I don't think that the reinforcers that occur at a global level stop just because the conflict is at a local level.  Americans in general want to see the bad guys stopped in any way possible.  With that attitude there are invariably serious mistakes.    

6.  Widespread availability of firearms ups the ante -

I have written about firearm related issues in many places on this blog.  My primary focus have been to suggest that violence, especially firearm related deaths including suicide, homicide, and mass shootings can probably be stopped by public health measures.  Very few people agree on those points and there are various political reasons why they do not.  Stopping firearm related violence does not necessarily require addressing firearms availability, but make no mistake about it - firearms access rather than mental illness is the number one cause of these deaths.  The problem with high risk scenarios involving either firearms or the threat of firearms with the police is even more obvious.  Statistics are available for the number of people killed by the police in a number of countries and the numbers are skewed in the expected manner toward the US.  It is clear that widespread availability of firearms is dangerous for both the police and the people who are being policed.  A lot of that comes down to being able to assess the threat and react in less than a half second.  That is the time a police officer has in a high threat scenario.

The six dimensions I briefly described are critical but unmentioned in the current debate.  The current debate is framed in terms of race, immutable interracial relationships, and a lack of scientific consideration at several levels.  At the cultural level, the notion of race having some specific meaning needs to be put to rest forever.  There is no scientific basis for classifying people based on skin color or other so-called racial characteristics.  Racial diversity is nothing compared with genetic diversity and that needs to be the new standard.  The second scientific consideration is based on the unique conscious state of humans.  This important concept should form the basis for everyone being treated with respect and consideration.  That is not to say that will preclude criminal conduct or violent acts against bystanders, but it should be a standard for everyone else.  The expression of anger especially sustained anger has a particular biasing effect that is never mentioned.  We hear that anger is appropriate or justified, and therefore it should be expected.  Appropriate, justified and expected anger still affects human decision making in a predictable way.  The angry - no matter who they are need to realize that they may not be seeing things clearly due to the predictable and biasing effects of that emotion.  The technical aspects of human reaction time and the fact that decision making in high threat situations does not improve - even with training is a sobering fact that all police officers need to deal with.  Given the quoted statistics, in high threat situations when a subject is armed - the outcome of that confrontation will essentially be a coin toss.  The only logical approach to the situation is to design a new situation where it does not come down to reaction time and every officer knowing they have a 50:50 chance of being able to shoot first.  There is an innate human tendency for conflict resolution by aggression and choosing sides on how that plays out is not the best way to resolve the problem.  All that I have seen in social media and the press highlights a string of arguments designed to support one side or the other.

Considering the science behind this problem will lead to permanent, long term solutions.          

George Dawson, MD, DFAPA


1: Murase D, Hachiya A, Fullenkamp R, Beck A, Moriwaki S, Hase T, Takema Y, Manga P. Variation in Hsp70-1A Expression Contributes to Skin Color Diversity. J Invest Dermatol. 2016 Apr 16. pii: S0022-202X(16)31047-8. doi: 10.1016/j.jid.2016.03.038. [Epub ahead of print] PubMed PMID: 27094592.

2: Yoshida-Amano Y, Hachiya A, Ohuchi A, Kobinger GP, Kitahara T, Takema Y,Fukuda M. Essential role of RAB27A in determining constitutive human skin color. PLoS One. 2012;7(7):e41160. doi: 10.1371/journal.pone.0041160. Epub 2012 Jul 23. PubMed PMID: 22844437; PubMed Central PMCID: PMC3402535.

3: Guo Z, Zhang Y, Zou L, et al. A Proteomic Analysis of Individual and Gender Variations in Normal Human Urine and Cerebrospinal Fluid Using iTRAQ Quantification. Pendyala G, ed. PLoS ONE. 2015;10(7):e0133270. doi:10.1371/journal.pone.0133270.

4:  Elena A. Ponomarenko, Ekaterina V. Poverennaya, Ekaterina V. Ilgisonis, et al., “The Size of the Human Proteome: The Width and Depth,” International Journal of Analytical Chemistry, vol. 2016, Article ID 7436849, 6 pages, 2016. doi:10.1155/2016/7436849.

5:  Skin specific proteome.  The Human Protein Atlas.  Accessed on 7/16/2016.

6:  Blair JP, Pollock J, Montague D, Nichols T, Curnutt J, Burns D.  Reasonableness and reaction time.  Police Quarterly Dec 2011; 14: 323-343 (especially pages 15-20).

7:  Nieuwenhuys A, Savelsbergh GJ, Oudejans RR. Persistence of threat-induced errors in police officers' shooting decisions. Appl Ergon. 2015 May;48:263-72. doi: 10.1016/j.apergo.2014.12.006. Epub 2015 Jan 16. PubMed PMID: 25683553.

8:  Lawrence H. Keeley. War Before Civilization. Oxford University Press, 1997.

9:  Chris Hodges.  War Is A Force That Gives Us Meaning. Public Affairs, New York, New York, 2002.


Attribution:  Graphic at the top is by Altaileopard SVG by Magasjukur2 [CC BY-SA 2.5 (], via Wikimedia Commons at:

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