Sherlock Holmes is undoubtedly
one of fiction's most popular characters,
having been portrayed by over 200 actors
on the screen over the years
and having served as the inspiration for other characters
such as Batman and Adrian Monk.
And it's no wonder why we're so fascinated with him.
Yes, his stories contain lots of mystery and adventure,
but he's also a character who can make
logical deductions from the most scant evidence,
and we find that inherently fascinating.
We find characters who are hyper-intelligent
to be really interesting.
And what's better about Sherlock Holmes,
he's not superhuman, he is human.
Which leads me to the point of this video,
because if you're anything like me,
you've probably gone beyond simple fascination
with the character at one point or another
and thought to yourself,
how can I think like Sherlock Holmes?
You know, without all the sociopathic tendencies
and the substance abuses, just the good parts.
Well that is what I want to explore in this video,
and by the end of it you're going to understand
three of the core mental strategies
that Holmes brought to his cases:
deep observation, skepticism, and probabilistic thinking.
(urban music)
The first strategy on my list
is also probably the most famous one;
Holmes is a keen observer of his environment.
He doesn't just casually see or perceive his environment
like the rest of us; he observes it with scrutiny,
taking it all in and storing away details
that other people would miss entirely
or forget really quickly.
This well trained power of observation
allows him to tie together all those small details
in order to make conclusions.
And this is a skill that's useful
not just in detective work, but in almost any field.
So here's how you can build this skill for yourself.
First, be an active participant
in whatever's going on in your life.
Try to be as present-minded as you can.
When you're having a conversation with somebody else,
try to listen actively.
Try to formulate questions in your head
to dig into what they're saying.
And when you're traveling around
or going about your business, don't be staring at your phone
or otherwise dividing up your attention.
Try to be present minded and observe your environment.
Like many other cognitive skills,
observation is a habit that can be strengthened over time.
The author W.I.B. Beveridge puts it really well
in his book The Art of Scientific Investigation:
"Training in observation follows the same principles
"as training in any activity.
"At first one must do things consciously and laboriously,
"but with practice the activities gradually become automatic
"and unconscious, and a habit is established."
Right now, most of us aren't very well trained
in the art of observation.
We divide up our attention; we multitask.
So again, if you want to get better at this,
be as present-minded as you can.
And to get specific, I do want to give you
one little challenge to take away from this video.
Next time you sit down to eat,
next time you sit down at a table,
don't take out your phone at all.
Not only will this force you to be
present-minded and not dividing your attention
with your phone and whoever's at the table,
but it'll also force you to make conversation
so that you'll be building your social skills as well.
Now, aside from mindfulness, there's one other
critical piece to building those observational skills,
and that's to gain experience in
whatever field that you want be
really perceptive and observational in.
Experts naturally pick out details
that are relevant to them in situations and environments
that the average person just isn't going to see.
Think about how a,
actually I can't say this word, what is it?
- Traceur.
- Yeah that, somebody who practices the art of parkour
would look at the average urban environment
versus how a normal pedestrian would look at it.
While you and I would just see
roads and sidewalks and buildings and other people,
somebody who's an expert in parkour
is going to see a lot more, naturally.
They're going to see the most efficient way
to get from Point A to Point B,
whether it's ducking under a railing
or vaulting over something, climbing up a wall.
And you and I are just not going to see that.
Now, this tip is pretty related
to another quality that Sherlock Holmes emphasizes a lot,
a background knowledge across many different fields
that's both deep, and most importantly,
according to Holmes himself, well curated.
This is a concept that Holmes calls the "brain-attic,"
and here's how he describes it in A Study in Scarlet:
"I consider that a man's brain
"originally is like a little, empty attic,
"and you have to stock it with such furniture as you choose.
"A fool takes in all lumber
"of every sort that he comes across,
"so that the knowledge which might be useful to him
"gets crowded out, or at best is jumbled up
"with a lot of other things, so that he has difficulty
"in laying his hands upon it.
"Now, the skillful workman is very careful indeed
"as to what he takes into his brain-attic."
Now, I don't think you need to be paranoid
about taking in the wrong things,
as the brain is pretty elastic
and you're really not going to "fill it up" as such.
But you do want to make sure that you're focusing
on the most important things for the majority of your time.
Most of us have that one person in our life
that's a master of useless trivia,
but hasn't really put a whole lot of time
into developing a useful skill.
Don't be that person.
Put the majority of your time and energy and focus
into gaining useful information.
And when you do, learn actively;
take notes, summarize what you learn,
and try to put it into practice as soon as you can.
Additionally, you want to be exploring
lots of other subjects that are somehow related
to your main subject.
Doing this will form lots of additional neural connections
and build a really deep web of information in your brain.
And memories that have lots of different connections
are both more likely to be retrieved
and more likely to be combined with the problem at hand
to come up with a creative solution.
As the famous investor and partner of Warren Buffet
Charlie Munger said, "The first rule
"is that you can't really know anything
"if you just remember isolated facts
"and try and bang them back.
"If the facts don't hang together
"on a lattice-work of theory,
"you don't have them in a usable form."
(urban music)
The second mental strategy of Sherlock Holmes
that we're going to cover today is skepticism.
The Athenian playwright Euripides once wrote that
"Man's most valuable trait is a judicious sense
"of what not to believe."
And Sherlock Holmes brings a natural skepticism
to every case that he faces.
He listens to his clients or observes the details
of a case or a crime scene deeply and scientifically,
but he also compares what he's seen and observed
to his current model of reality
and all of his background knowledge.
But on the other hand, as studies have found,
most of us can't help but instinctively believe
what we hear right when we hear it,
especially if we're put in stressful situations
or we're put under time pressure.
Not only that, but our brains also rely
on lots of different little cognitive biases
and heuristics, mental shortcuts
that are very useful in many different situations,
especially as the human species evolved,
but that can also lead to incorrect decision-making
and bad thinking.
For instance, we tend to weight
the information that is available to us much too heavily,
that's called the availability heuristic.
We also tend to believe things
if we know a lot of other people believe them,
the bandwagon effect.
And we also rely heavily on stereotypes.
In fact, a recent study in The Journal of Criminology,
which I think Holmes probably would have read,
found that certain physical traits
are correlated with sentencing decisions.
This being despite the fact that logically,
we all know that our physical appearance
has nothing to do with whether or not we committed a crime.
And that isn't even the half of it.
Environmental factors that you wouldn't expect
also have the ability to really influence
our decision-making.
For instance, prospective students
that visit a college campus on a cloudy day
are more likely to enroll in that college
than if they did on a sunny day.
And people who are affected by seasonal affective disorder
tend to make more risk-averse decisions with their money
during the winter months than they do
during the summer months.
Now with all these natural flaws in our thinking,
how can we actually think objectively?
One powerful strategy comes from the author Maria Konnikova,
who wrote the book Mastermind:
How to Think Like Sherlock Holmes,
which was, as you might guess,
one of the big inspirations for this video.
Her advice is to actively work
on noticing what is priming your thoughts
and influencing your decisions.
As she states in the book, "A prime stops being a prime
"once we're aware of its existence.
"Bring any attention at all to the priming mechanism
"and you'll likely find the effect go down to zero.
"When we're aware of the reason for our action,
"it stops influencing us."
And as we'll add on to that piece of advice,
make sure that when you come to a conclusion,
you can point to the logical deduction
or the observable evidence that caused it.
If you can't, then it's a good sign
that you're relying on one of those cognitive biases
and that you should probably work through the problem
a little bit more deliberately again.
(urban music)
Finally, Sherlock Holmes' ability
to make deductions and solve cases
hinges on his ability to think in terms of probabilities.
What is most likely to happen?
When Holmes is working on a case, he thinks
like a scientist, and he uses the scientific method,
forming hypotheses as he goes along
and testing them against new data as it's discovered.
And since that data is almost never 100% conclusive,
he generates many different hypotheses,
and then he tries to figure out
which one is the most likely candidate.
Now, this probabilistic thinking
is also called inductive reasoning.
While deductive reasoning uses certainty and sound logic
to reach conclusions that are 100% true,
inductive reasoning asks what is the mostly likely answer,
given the facts?
And again, since most complex problems in life
usually rely on incomplete information,
you need to be able to use inductive reasoning
just as much as you need to be able to use
deductive reasoning.
Now if you want to see this probabilistic thinking in action
one of the Holmes stories, "The Sign of Four,"
has a great example.
It starts when Dr. Watson hands Holmes a pocket watch
and asks what he can deduce from it.
After looking the watch over for a few seconds,
Holmes replies with quite a lot of information, actually.
That the watch was originally owned by Watson's father,
then passed down to his elder brother.
Also that his older brother had certain periods of his life
that were prosperous, but spent most of it in poverty
and probably ended up dying of alcoholism.
Now, this deduction turns out to be extremely accurate,
and at first Watson is offended,
thinking that Holmes had actually dug into his personal life
and that he was being a charlatan, but Holmes insists
that he didn't even know Watson had a brother
until looking at the watch.
All of his deductions were based on
the observations he gained from the watch
and probabilistic thinking.
Now if you're curious about all these details
I highly recommend going and reading the story.
Since it is public domain, you can read it for free.
But for an example, he does note
that the alcoholism deduction came from the fact that
there were scratches around the keyhole, and a sober man
would have never put scratches around the keyhole
because he wouldn't have missed the keyhole
when trying to open the watch.
And moving away from the realm of fiction,
if you want a more practical example,
I've found that probabilistic thinking
can actually help you find things that you've lost
a lot more quickly than
the most commonly recommended solution
which is to mentally retrace your steps.
Now that can work pretty well,
but it encourages linear thinking, which can waste time.
If you think probabilistically, and you ask yourself
what is the most likely place I would have, say,
taken out my wallet, what is the most likely place
I was really distracted and might have set it down,
you may end up finding it faster
and that could be the difference
between somebody picking it up and making off with it
and you actually getting it back.
Now, there are lots of other techniques
that Sherlock Holmes used, which we could do
tons of different videos on.
But one of the them, which Sherlock
would have surely used in his investigations,
and which is very closely related to probability,
is game theory.
And if you'd like to find out what game theory is,
and how you can use it as an extremely effective
decision-making tool for solving problems,
you should definitely check out this video
that I made with my friend Jade
over at her channel, Up and Atom.
Not only will the video teach you
about game theory in general, but because it uses
multiple choice questions as a case study,
you're also going to learn a technique
that'll help you potentially get fewer wrong answers
on your own tests in the future.
And by the way, it is not something
I talked about in my multiple choice video,
so you're definitely going to want to check it out.
Also, you might notice that there
is not an ad at the end of this video.
That's because I made this video
as part of Skillshare's Spotlight program,
where they use their time and ad budget
to help highlight small creators who are doing great things.
Jade's channel is in the Spotlight this month,
and it focuses on topics like physics
and math and cryptography and lots of other cool stuff,
so if you enjoy this video on game theory
definitely subscribe to her channel.
In fact, I'm not going to put any
of the other call-to-action things
I usually put in my videos here,
because I want you to just go watch this video
and subscribe to Jade.
Other than that guys, thank you so much for watching;
hopefully you found this video helpful
and I will see you in the next one.