Some further considerations about Sgt. Donovan and cognitive biases



This post was inspired by a very interesting private conversation, in turn originated by this post.

The intriguing question that emerged in that conversation - and that I think might be of interest for other people, too - is this:

Is it possible that, along with the other very legitimate dynamics that are probably at play, Donovan might be genuinely worried that Sherlock could be dangerous, especially given the propensity for serial killers to watch or even try to participate in police investigations of their crimes?


Well, folks, this is REALLY a complex question, which involves very complicate cognitive dynamics I can only try to unravel, here.
Let’s start with a summary of my answer: yes, it’s perfectly possible that Sally’s concerns are genuine, and at the same time they could also be biased by her prejudices.

Let’s try to summarize what - according to me - affected Donovan’s judgment about Sherlock in general, and Sherlock’s involvement in the kidnapping, in tRF, in particular (about which, I’d suggest you to previously read this specific post).
I wrote that I’m persuaded that her evaluations about Sherlock are biased, but her errors were made in good faith, and are mainly due to prejudices she is not aware of - better: she is of course aware of her bad opinion about Sherlock, but she is probably not consciously aware of the very subjective elements which foster it, and which could be so summarized: 

  • A - very understandable - annoyance at Sherlock’s bad manners and lack of any form of tact in his interactions with her and, more generally, all the police officers.
  • A - also understandable, and quite common, on the workplace - feeling of being in some way threatened and diminished, in her professional capacity, by Sherlock.
  • The effect on her of that “esprit de corps” which any group or team experiences, and according to which any member of a group distrusts and dislikes any outsider who tries and meddles with the group’s businesses.
  • The further irritation generated whenever this outsider, which has access to police investigations he shouldn’t have access to, takes the liberty of refusing a request of help which her direct superior lowered himself to bid him (thus further humiliating all of them).
All of these elements would be perfectly sufficient, even alone, to generate and nurture  that subtle prejudice that, in the end, led Donovan to accept so quickly the idea that Sherlock could be a fraud, and that all the crimes he solved could have been actually perpetrated and staged by him, despite the lack of any proper evidence, and, on the contrary, the extreme ambiguity and inconsistency of the clues the police possessed.


But the problem with prejudice is that it’s insidious and tend to wrap itself in rational, factual and true elements, and in this way it can bias even perfectly normal and clever people’s judgment - just as Moriarty did in order to destroy Sherlock: a lie wrapped in little scraps of truth, so that people “will swallow it”.

What I mean is that there are (over-simplifying…) two kinds of prejudices, in this world: those blatant prejudices (for example, about the “inferiority” of certain “races”, the “unreliability” of women, and so on) which can become established through blind traditionalism and/or hammering propaganda, but which generally don’t take a hold over adult people with a passable IQ and a decent education (i.e., with a developed enough critical attitude); and more subtle - and therefore MORE DANGEROUS - prejudices which can take a hold, unseen and silent, over almost each one of us, even the cleverest and most well-read ones, if we are not constantly on our guard against them.
This latter kind of prejudices are quite often facilitated by the social, cultural, and organizational environment in which we live and work and interact with other people. They are not blatant, they “float in the air” and are assimilated almost by osmosis by unaware people, even because they generally find some kind of anchoring in some real fact or data, even if that real fact of data is then distorted through the “lens” of the prejudice itself.
After all, the literal meaning of pre-judice is just “to judge in advance” - that is, as canonical Holmes said, disapprovigly (WIST), to put your theories in front of your data (which you generally do by selecting some partial data, upon which you build a theory which, should ever be confronted with the entirety of the available data, could never hold).
This is what Sgt. Donovan does with regard to Sherlock - and she does it, as I said, in good faith. That same “terrible” good faith that is behind many of the most terrible miscarriages of justice, for instance.
What I mean, is that I’m persuaded that she is genuinely worried that Sherlock could be dangerous - a “dangerous psychopath”; but also that, even if she can’t consciously realize this, she “built” this fear in order to justify her prejudice, to give it some plausible, rational foundations, to present it as a reasonable and objective evaluation of Sherlock - to herself, before than to anyone else.
And this kind of mental (generally unconscious, I reiterate) operation, generally requires a realistic, factual starting point.
For Sally, the starting point is the - empirically founded - idea that some kinds of criminals (such as pyromaniacs and certain kinds of serial killers) sometimes enjoy to watch closely - and possibly participate into - police (or other agencies) investigations (or interventions) into their crimes (for instance, many pyromaniacs have a past of failed applications to the fire brigade, and some of them even succeed in entering the corps…). This is the little truth to begin with.
But, on this little truth, an illogical reasoning is built.
Because, if it’s true that some (but not all) “psycopaths” enjoy following, and even taking part into, police investigations of their crimes, it’s TOTALLY FALSE that any person who enjoy following or taking part into police investigations is a psychopath (actually, the very vast majority is NOT).
The simple fact that Sherlock “gets off” on working on police cases doesn’t really reveal ANYTHING about him potentially being a dangerous criminal - it is a totally inconclusive clue. But Sally probably READS it as a confirmation of a “diagnosis” she has already made out of elements and considerations - the ones I listed above - which have nothing to do with any psychiatric problem on Sherlock’s part, and all to do with Donovan’s SUBJETIVE (albeit understandable) problems with him.
It’s a problem of FRAME. 
Mark Twain used to say that a man who holds a hammer tends to perceive everything as a nail. In the same way, whenever we have a certain image of a person, we tend to read any action or word he/she takes or utters conferring it a meaning which could be coherent with that image. We even selectively draw from our patrimony of knowledges and experiences in order to find and use those - and ONLY those - which could help in confirming our idea (while the scientific method teaches - or should teach - us that we should always try to prove it wrong - so-called falsification test). And if they don’t fit perfectly, we imperceptibly and unconsciously TWIST them in order to fit.
Sally has no real, objective and unequivocal element to think that Sherlock might really be a “psychopath” (as NOBODY else has…). Yet she appears genuinely - i.e., in good faith - persuaded of this, and thus, of course, also concerned about this.
Because she unconsciously framed Sherlock as such. She took a little, real data (Sherlock “gets off” on weird police cases) and combined it with another little data (some mentally disturbed criminals get off on police investigations about their crimes) into a fallacy - a paralogismus - according to which “every person who gets off on a crime investigation is a psychopath”. It’s like saying that, because all chickens have two legs, and Socrates has two legs, Socrates is a chicken… Of course Donovan is clever enough to spot the fallacy in the case of the “Socrates and chickens” paralogismus; but when it comes to Sherlock, she is blinded by her prejudices against him: her concerns, albeit superficially founded, on a closer and more careful review appear totally devoid of logic and grounding. But, TO HER, they remain GENUINE, sincere.
Here is the devilish trap of prejudice, which can catch even clever and well-intentioned people. Which, I think, Donovan on the whole is.