August 1, 2025 • 24 mins
In this #StudyFinds episode of #ProveItPod, Dr. Matt Law dives into a recent study that explores how sleep can affect dark personality traits. Are your sleep habits sending you to the dark side? Listen now to find out!
Episode Resources:
Poor sleep can bring out workers' darker side, study finds - Safety+Health Magazine
Kuijpers, E., Vergauwe, J., Vanderperre, S., Mairesse, O., & Hofmans, J. (2025). Rise of the Dark Side: How Sleep Perception Triggers Dark Triad States at Work. Journal of Organizational Behavior. https://doi.org/10.1002/job.2885
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:47):
Hello, everyone,
and welcome to Prove It To Me.
I'm your host, Dr.
Matt Law.
If you haven't heard, next week,
August 4-6,
is the Board of Certified Safety
Professionals Research and Innovation
Summit in Indianapolis.
What is the R&I Summit, you ask?
This is a biennial event that serves as
a forum for leaders, practitioners,
(01:08):
researchers,
and students in the occupational and
environmental safety and health space.
At each R&I Summit,
I've had the privilege of sitting and
speaking with the people who are on the
forefront of innovation.
These aren't just big ideas,
these are actionable and researched
concepts.
You don't walk away empty-handed from
this one.
On Wednesday afternoon,
(01:29):
I will also be presenting my ongoing
research into professional credibility
in the safety profession.
Of course,
this is my own personal research that
I've been doing in my spare time and
not really associated with anyone I
work for,
but anyone who comes will get to engage
in a lively discussion about
credibility and take away some evidence
-based action items.
(01:51):
Oh,
and I will almost certainly take this
opportunity to recruit some guests for
the Prove It To Me podcast.
This is research and data after all,
so why not?
I know you all are tired of hearing
from just me.
So hey,
if you're not registered and this
little announcement has got you feeling
a little FOMO, I totally get that.
(02:11):
I'm pretty sure you can still get in on
the action by registering as a virtual
attendee from now until August 5th.
Just go to bcsp.org slash events to
learn more.
I'm very excited to see everyone at the
BCSP R&I Summit next week,
but now it's time to jump into our
topic for today.
Now a lot of folks know I'm a Trekkie.
(02:33):
Or Trekker?
There's a debate in the Star Trek
fandom on the correct term, but anyway,
yeah, I'm a huge fan of Star Trek.
All of it.
And I don't hide that,
I actually make it super obvious.
If you see me at a conference,
I'm almost always wearing a Star Trek
Delta on my lapel.
I do this for a number of reasons.
(02:54):
Number one.
Number one, yeah, first of all,
it's a great conversation starter.
Since Star Trek has been a thing since
the late 60s,
the Delta is pretty recognizable by
just about anyone,
whether they're a fan or not.
So people often come up to me and point
it out.
(03:15):
Since I am, by most accounts,
an introvert,
this is my own mini icebreaker.
I can always start a conversation about
Star Trek,
whether you want that conversation or
not.
But also,
the franchise means a lot to me.
As an adult, the way that I lead,
the way that I pursue new things with
curiosity,
(03:35):
the optimism with which I try to see
the future of people and how we
interact with the world and the
universe,
all of that is heavily influenced by
Star Trek.
And because it means so much to both my
personal and professional life,
I carry it with me very openly.
But I wasn't always this big of a
Trekkie.
(03:55):
In fact,
this is something that has only become
such a big part of my life in my adult
years.
Sure,
I caught a few episodes of The Next
Generation when I was a kid,
but there are some very adult concepts
in Star Trek that I never understood
back then.
Now I get it, and I love it.
When I was growing up,
I was a Star Wars fan.
(04:16):
I'm still a big Star Wars fan,
but I've just made room for other
things in my adult life.
Again,
this franchise also means a lot to me.
I think the fandom can be very toxic,
so you probably won't find me in any of
the Star Wars social media groups.
I'm the guy that loves every movie and
every episode for all their faults,
(04:38):
and if I do criticize something,
it's usually in good fun.
Not with hate, malice,
or dismissal of its legitimacy.
I do love the prequels,
and I love that they've had such a
resurgence because of their,
how do I say this, meme-ability.
I'm also a fan of the sequels.
and just about everything they've done
with the Disney shows.
(04:59):
If for nothing else,
it's because I felt so siloed as an
avid Star Wars fan as a kid.
I had very few friends who were as big
of fans as I was.
Now it's like all of these fans came
out of the woodwork.
Being a Star Wars fan is mainstream.
We even have theme parks and big budget
video games for Star Wars now.
(05:20):
It's cool to be a Star Wars fan and
that is mind blowing to me.
I should emphasize that no,
the Jedi are not my favorite part of
Star Wars.
I mean, yeah,
lightsaber battles are cool,
but I love the underground stuff,
the smugglers and bounty hunters and
spies and criminal underworld part of
Star Wars.
(05:40):
That's what gets me going.
Give me a blaster over a lightsaber all
day.
Yeah,
so now that I've geeked out on sci-fi
for longer than I probably should have,
it's time to dig into what I found this
week that caught my eye kind of.
because of this fandom that I've held
on to for more than a few decades.
(06:01):
In June of this year,
the National Safety Council's Safety
and Health Magazine published a short
article titled,
Poor Sleep Can Bring Out Workers'
Darker Side Study Finds.
Now,
the reason I wanted to click on this is
twofold.
First,
we're talking about the dark side,
not the dark side of the force,
but the dark side of personality.
(06:21):
And everybody knows that we all have a
dark side.
Whether we embrace it or not, well,
perhaps that depends on your awareness
of it and what lessons you took from
Star Wars.
Second, I'm just wondering,
can you really measure someone's dark
side?
Like,
it's definitely one of those things
that when you see it,
you know what it is.
(06:43):
But to me,
it seems like one of those soft things
that would be difficult to measure.
One of those things that a psychologist
might talk about,
but really just ends up being a talking
point rather than something that can be
tangibly managed.
Oh, and also, this is about sleep.
And I am acutely aware of my sleep
habits.
(07:03):
I don't do well if I have less than
seven hours of sleep at night.
I know this is also supported by lots
and lots of research.
I even remember a study that came out
more than a decade ago that linked
early onset of dementia with
consistently getting less than seven
hours of sleep at night.
Between that and what I know to be the
immediate impacts of poor sleep for
myself,
(07:24):
I have always placed a priority on
getting enough sleep,
even if it takes earplugs and a good
dose of melatonin and diphenhydramine,
TMI.
Anyway,
the Safety and Health Magazine article
briefly discusses the study and these,
quote,
dark triad states and suggests that
employers should promote healthy sleep
(07:44):
habits and foster a positive work
culture.
Thankfully, they linked to the study.
So let's take a deeper look at how this
was put together and what they found.
This study...
was published in March of 2025 in the
Journal of Organizational Behavior and
is titled Rise of the Dark Side.
Oh yes,
(08:04):
I love it when researchers get geeky in
their titles.
Rise of the Dark Side,
How Sleep Perception Triggers Dark
Triad States at Work.
The study took place primarily in
Belgium but also had participants in
Argentina due to family connections and
the authors declared no competing
interests.
(08:25):
They've also made the data for this
study openly available in the open
science framework,
which is really cool.
That means the researchers are really
not trying to hide anything and they
are open to both further research and
critical feedback from other
researchers.
It's a sign of strong confidence in the
work they did.
So let's start by looking at how the
(08:46):
authors introduced the topic.
Apparently there has been a lot of
interest in studying the dark side of
personality.
specifically focused on dark triad
traits.
These traits are narcissism,
psychopathy, and Machiavellianism.
How are each of these defined?
Narcissism is characterized by a strong
drive for self-enhancement,
(09:07):
seeking admiration,
and recognition from the social
environment.
Huh.
That actually describes…
me.
Maybe it's the real reason for this
side.
Well, anyway, I knew this already,
(09:27):
although I do mostly counteract my
narcissism with self-deprecation.
So that's narcissism.
Let's look at Machiavellianism.
Machiavellianism is defined as a
strategy of social conduct that
involves manipulating others for
personal gain,
often at others' expense.
Okay,
now I need to state that even though I
(09:50):
may have manipulated some of you into
listening to this podcast,
as of this recording,
I have gained little other than my own
catharsis in this creative endeavor.
It's a money pit rather than a money
maker.
You're welcome.
Lastly, there is psychopathy.
Psychopathy is shaped by a persistent
(10:10):
disregard for social norms,
lack of empathy,
and an absence of remorse or guilt.
Okay, that's not me.
I don't think, anyway.
Now,
I can conceptualize that these traits
would be measurable.
Like,
you could probably do it with self-reported
feelings using a Likert scale.
(10:31):
The Likert scale, if you don't know,
is a scale that you see on surveys
where you answer on a scale of 1-5 or 1
-10 or strongly agree to strongly
disagree.
That's a Likert scale.
Anyway,
between that and behavioral observations,
I'm sure you could measure these well
-defined traits of narcissism,
psychopathy, and Machiavellianism.
(10:53):
And the authors state that these have
been studied quite a bit over the last
20 years.
They even point out that,
as studied in the work environment,
these traits,
when moderately displayed,
can have a somewhat positive outcome,
such as in leadership context.
Have you ever heard that most CEOs are
psychopaths?
(11:14):
I imagine this research is where that
comes from.
The other parts of this is that the
authors state that much of previous
research has focused on personality
traits being stable,
meaning that narcissism, psychopathy,
and Machiavellianism, and even,
I guess let's call it light-side
personality traits,
would be considered constant in these
(11:35):
studies.
Their argument is that more recent work
has looked at these personality traits
being more malleable,
and they may be influenced by other
factors.
So, if you ever meet someone that says,
people can change,
or that desperate girl that says,
I just feel like I can fix him." They
might be halfway right anyway,
(11:56):
but it might not be your influence that
changes the strength of a personality
trait in another person.
Instead, it may be their environment,
their work, and in this study,
perhaps their sleep quality.
This may be further supported by
research that suggests that self
-regulation is needed to suppress dark
personality trait tendencies.
(12:17):
When you are stressed, fatigued,
less attentive,
or if you lack the cognitive resources
due to a heavy cognitive load,
you're coping with stress,
you feel threatened,
or if you're hungry,
apparently it's more likely that these
dark traits will surface.
All of this sets up the first part to
(12:37):
how they did this study and the model
that they used.
Remember,
models don't tell you how things
actually work.
They conceptualize how things might
work and tell you the data points to
measure to determine relationships
between the variables.
This model,
called the strength model of self
-control,
was introduced by Baumeister and Newman
(12:58):
in 1994.
The model suggests that controlled,
willful action quickly consumes and
depletes inner resources resulting in
self-control failure,
and you must have rest and sleep to
replenish those resources of self
-control.
The authors presented previous research
that has linked a lack of sleep to
(13:20):
increases in irritability,
altered responses to frustration,
tendencies to blame other people for
problems, lowered empathy,
and lower distress tolerance.
So their first presented hypothesis is,
quote,
sleep quality and quantity are negatively
related to dark triad states at work.
(13:41):
Good.
That's measurable.
Basically,
that means that what they expect to
find is that an increase in sleep
quality and quantity will result in
lower prevalence.
of narcissism, psychopathy,
and Machiavellianism.
Of course,
the inverse would also be true,
if this was the case.
They also wanted to study this idea of
(14:02):
distress tolerance.
Individuals with low distress tolerance
are expected to report distress as
unbearable,
struggle to handle being distressed or
upset,
and increasingly use impulsive behaviors
to alleviate distress.
So their second hypothesis is, quote,
distress tolerance mediates the
(14:23):
negative relationship between sleep
quality and quantity on the one hand
and dark triad states on the other hand
in such a way that better sleep, i.e.
higher sleep quality and longer
sleeping hours,
relates to higher distress tolerance,
which in turn relates to less dark
triad state expressions.
(14:44):
Do you remember what mediation is?
Previously,
we talked about mediating and
moderating variables.
A mediating variable serves as the go
-between for two variables,
explaining how two variables are
related,
whereas a moderating variable affects
the strength and direction between two
variables.
So what the authors are hypothesizing
(15:06):
here is that distress tolerance
explains the negative relationship
between sleep and dark personality
traits.
So let's look at how they designed the
study.
The authors used a 10-day experience
sampling method among 103 employees
making 786 repeated observations.
(15:27):
The experience sampling method is a
research technique that involves
collecting data about individuals'
thoughts, feelings,
and behaviors in their natural
environments at multiple points in
time.
This is actually a good way to do this
and reduce what's called recall bias,
which is an error you can get when your
participants inaccurately or
incompletely remember their past
(15:48):
events.
So they recruited workers from one of
the authors' social networks,
so it's a convenience sample.
We've also talked about that before.
Sometimes you have to work with what
you have.
It makes the study less experimental as
far as sampling goes,
but there are plenty of ways to control
the bias and make the best of it.
(16:08):
Participants received two
questionnaires every day,
one in the morning where they were
asked to report on their sleep quantity
and quality,
and one in the afternoon where they
reported on their distress tolerance
and dark triad states of that workday.
Now already I can see where you could
probably strengthen the study a bit if
you gave them all sleep trackers and
(16:29):
got a more accurate score,
but I get that may not have been
feasible.
They did a pretty good job of data
cleanup here,
eliminating duplicate responses,
unmatched morning and afternoon
responses,
and observations where the afternoon
survey was completed before the morning
survey.
The final sample had 57 folks from
(16:50):
Belgium, 46 from Argentina,
average age was 42 years,
and pretty much half male and half
female.
The only statistically significant
differences they had between the groups
was that Belgian participants scored
higher on average distress tolerance
and Argentinian participants scored
higher on average dark triad states.
(17:11):
As I suspected,
they used the Likert scales to measure
sleep quality, distress tolerance,
narcissism, psychopathy,
and Machiavellianism.
The authors also talk about the power
of their sample.
Basically,
this is a statistical test you can use
to figure out how strong your sample
size is based on the number of
participants you have and the type of
(17:32):
statistical test you are using for your
correlation analysis.
They admit to having a small effect
size of 0.14.
For reference, the scale is 0 to 1,
with 1 being the largest effect size.
This doesn't mean that the results
don't mean anything,
it's just a way to say,
take this study for what it is with the
(17:53):
sample we had,
and we probably need to have a larger
sample size in the future to verify the
results.
They also used intraclass correlation
coefficient measurements to test the
reliability of multiple measurements of
the same variable.
Basically,
they found that a fairly high
percentage of the variation in the dark
triad, distress tolerance,
(18:14):
and sleep quality and quantity were due
to within-person variation in those
constructs.
Now, let's get to hypothesis testing.
They used a two-level regression model,
which is fantastic,
to test between dark triad states and
sleep quality and quantity.
They found that sleep quality and
(18:35):
quantity had a statistically
significant negative relationship with
the dark triad states.
Sleep quality and quantity accounted
for 74.6% of the variance in
Machiavellianism,
75% of the variance in psychopathy,
and 70.8% of the variance in
narcissism.
These are big numbers for accounting
(18:55):
for variance.
Additionally,
they did find that distress tolerance
effectively mediated this relationship.
Sleep quality statistically
significantly impacted distress
tolerance,
and distress tolerance statistically
significantly impacted the dark triad
states.
Same for sleep quantity.
(19:15):
However,
they noted that this was only a partial
mediation in both cases based on their
test results.
Now,
they also did some additional analyses,
which you can totally do if you already
have the data.
It's kind of a fuck it,
why not scenario.
I end up doing this all the time in my
own research.
Having the data sparks even more
(19:36):
curiosity.
One interesting point is that they
found participants with higher average
dark state levels,
meaning they probably display these
traits stronger anyway, had even...
stronger elevated dark state
expressions in response to poor sleep.
So if you are already naturally on the
dark side,
(19:56):
a bad night's sleep is only going to
exacerbate the problem and more so than
for anyone else.
The other test was for reciprocal
effects.
So instead of sleep affecting the dark
triad states,
how do dark triad states affect sleep?
Interestingly,
Machiavellianism predicted increased
(20:17):
sleep quality and quantity,
and narcissism negatively predicted
sleep quality and quantity.
However,
the calculated variance was very
minimal,
less than 5% for each of these.
So what are the practical implications
for this?
Well, first of all,
the authors state that these dark
personality traits can negatively
affect work performance and work
(20:38):
culture as supported by previous
research.
They also suggest that since sleep can
be influenced by many different
factors.
not just drugs,
they encourage employers to promote
healthy sleep habits.
And this isn't just telling your
employees, hey, go get some sleep.
For example,
they could limit overtime and shift
work,
(20:59):
provide flexible working arrangements,
establish policies that discourage
working more than a set number of hours
without rest,
and insistence on taking scheduled
breaks.
A sleep education could also be an
effective intervention.
The authors also bring up this idea of
allowing daytime napping at work,
although it's taboo in many workplaces.
(21:21):
I don't know.
Have you ever taken a nap during
working hours?
I'm not above admitting that I've done
it.
And even though I may work later
because I did,
I felt a lot more productive afterward,
perhaps a bit less narcissistic too.
All right, finally,
let's look at their limitations.
They talk about the limitations to
measuring sleep quality and quantity in
(21:42):
the way they did,
which they think they can mitigate by
capturing this metric closer to wake
time.
They also suggest wearable sleep
trackers would be more accurate,
which is exactly what I said earlier.
They said they could validate a new
instrument in the future,
which uses better phrasing to measure
the personality states,
also cultural differences in sleep and
(22:04):
napping habits between Belgium and
Argentina could have impacted the
results.
Another thing that wasn't measured is
the fact that even if someone has the
cognitive ability to suppress dark
tendencies,
they may still choose not to suppress
them.
And lastly,
they like to see the daytime napping
element explored better in the future.
(22:25):
So ultimately this was a very well
executed study, in my opinion.
It's hard to argue that a bad night's
sleep will negatively impact your day.
However,
this study put some numbers to sleep's
effect on your bad personality.
So the next time you run into someone
who's being a little too narcissistic
or or psychopathic,
(22:47):
just think about this.
It may not be about the side of the bed
they woke up on after all.
It may just be that they suck at
sleeping.
With that being said,
I'm gonna go take a nap.
I'm Dr.
Matt Law,
and this has been another great episode
of Study Finds on the Prove It To Me
podcast.
Take care and stay safe, everyone.
(23:10):
["Study Finds on the Prove It To Me"]
Prove It To Me is produced by me,
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(23:32):
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(23:52):
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(24:13):
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(24:34):
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the host.
Hello, everyone,
and welcome to Prove It To Me.
I'm your host, Dr.
Matt Law.
If you haven't heard, next week,
August 4-6,
is the Board of Certified Safety
Professionals Research and Innovation
Summit in Indianapolis.
What is the R&I Summit, you ask?
This is a biennial event that serves as
a forum for leaders, practitioners,
(01:08):
researchers,
and students in the occupational and
environmental safety and health space.
At each R&I Summit,
I've had the privilege of sitting and
speaking with the people who are on the
forefront of innovation.
These aren't just big ideas,
these are actionable and researched
concepts.
You don't walk away empty-handed from
this one.
On Wednesday afternoon,
(01:29):
I will also be presenting my ongoing
research into professional credibility
in the safety profession.
Of course,
this is my own personal research that
I've been doing in my spare time and
not really associated with anyone I
work for,
but anyone who comes will get to engage
in a lively discussion about
credibility and take away some evidence
-based action items.
(01:51):
Oh,
and I will almost certainly take this
opportunity to recruit some guests for
the Prove It To Me podcast.
This is research and data after all,
so why not?
I know you all are tired of hearing
from just me.
So hey,
if you're not registered and this
little announcement has got you feeling
a little FOMO, I totally get that.
(02:11):
I'm pretty sure you can still get in on
the action by registering as a virtual
attendee from now until August 5th.
Just go to bcsp.org slash events to
learn more.
I'm very excited to see everyone at the
BCSP R&I Summit next week,
but now it's time to jump into our
topic for today.
Now a lot of folks know I'm a Trekkie.
(02:33):
Or Trekker?
There's a debate in the Star Trek
fandom on the correct term, but anyway,
yeah, I'm a huge fan of Star Trek.
All of it.
And I don't hide that,
I actually make it super obvious.
If you see me at a conference,
I'm almost always wearing a Star Trek
Delta on my lapel.
I do this for a number of reasons.
(02:54):
Number one.
Number one, yeah, first of all,
it's a great conversation starter.
Since Star Trek has been a thing since
the late 60s,
the Delta is pretty recognizable by
just about anyone,
whether they're a fan or not.
So people often come up to me and point
it out.
(03:15):
Since I am, by most accounts,
an introvert,
this is my own mini icebreaker.
I can always start a conversation about
Star Trek,
whether you want that conversation or
not.
But also,
the franchise means a lot to me.
As an adult, the way that I lead,
the way that I pursue new things with
curiosity,
(03:35):
the optimism with which I try to see
the future of people and how we
interact with the world and the
universe,
all of that is heavily influenced by
Star Trek.
And because it means so much to both my
personal and professional life,
I carry it with me very openly.
But I wasn't always this big of a
Trekkie.
(03:55):
In fact,
this is something that has only become
such a big part of my life in my adult
years.
Sure,
I caught a few episodes of The Next
Generation when I was a kid,
but there are some very adult concepts
in Star Trek that I never understood
back then.
Now I get it, and I love it.
When I was growing up,
I was a Star Wars fan.
(04:16):
I'm still a big Star Wars fan,
but I've just made room for other
things in my adult life.
Again,
this franchise also means a lot to me.
I think the fandom can be very toxic,
so you probably won't find me in any of
the Star Wars social media groups.
I'm the guy that loves every movie and
every episode for all their faults,
(04:38):
and if I do criticize something,
it's usually in good fun.
Not with hate, malice,
or dismissal of its legitimacy.
I do love the prequels,
and I love that they've had such a
resurgence because of their,
how do I say this, meme-ability.
I'm also a fan of the sequels.
and just about everything they've done
with the Disney shows.
(04:59):
If for nothing else,
it's because I felt so siloed as an
avid Star Wars fan as a kid.
I had very few friends who were as big
of fans as I was.
Now it's like all of these fans came
out of the woodwork.
Being a Star Wars fan is mainstream.
We even have theme parks and big budget
video games for Star Wars now.
(05:20):
It's cool to be a Star Wars fan and
that is mind blowing to me.
I should emphasize that no,
the Jedi are not my favorite part of
Star Wars.
I mean, yeah,
lightsaber battles are cool,
but I love the underground stuff,
the smugglers and bounty hunters and
spies and criminal underworld part of
Star Wars.
(05:40):
That's what gets me going.
Give me a blaster over a lightsaber all
day.
Yeah,
so now that I've geeked out on sci-fi
for longer than I probably should have,
it's time to dig into what I found this
week that caught my eye kind of.
because of this fandom that I've held
on to for more than a few decades.
(06:01):
In June of this year,
the National Safety Council's Safety
and Health Magazine published a short
article titled,
Poor Sleep Can Bring Out Workers'
Darker Side Study Finds.
Now,
the reason I wanted to click on this is
twofold.
First,
we're talking about the dark side,
not the dark side of the force,
but the dark side of personality.
(06:21):
And everybody knows that we all have a
dark side.
Whether we embrace it or not, well,
perhaps that depends on your awareness
of it and what lessons you took from
Star Wars.
Second, I'm just wondering,
can you really measure someone's dark
side?
Like,
it's definitely one of those things
that when you see it,
you know what it is.
(06:43):
But to me,
it seems like one of those soft things
that would be difficult to measure.
One of those things that a psychologist
might talk about,
but really just ends up being a talking
point rather than something that can be
tangibly managed.
Oh, and also, this is about sleep.
And I am acutely aware of my sleep
habits.
(07:03):
I don't do well if I have less than
seven hours of sleep at night.
I know this is also supported by lots
and lots of research.
I even remember a study that came out
more than a decade ago that linked
early onset of dementia with
consistently getting less than seven
hours of sleep at night.
Between that and what I know to be the
immediate impacts of poor sleep for
myself,
(07:24):
I have always placed a priority on
getting enough sleep,
even if it takes earplugs and a good
dose of melatonin and diphenhydramine,
TMI.
Anyway,
the Safety and Health Magazine article
briefly discusses the study and these,
quote,
dark triad states and suggests that
employers should promote healthy sleep
(07:44):
habits and foster a positive work
culture.
Thankfully, they linked to the study.
So let's take a deeper look at how this
was put together and what they found.
This study...
was published in March of 2025 in the
Journal of Organizational Behavior and
is titled Rise of the Dark Side.
Oh yes,
(08:04):
I love it when researchers get geeky in
their titles.
Rise of the Dark Side,
How Sleep Perception Triggers Dark
Triad States at Work.
The study took place primarily in
Belgium but also had participants in
Argentina due to family connections and
the authors declared no competing
interests.
(08:25):
They've also made the data for this
study openly available in the open
science framework,
which is really cool.
That means the researchers are really
not trying to hide anything and they
are open to both further research and
critical feedback from other
researchers.
It's a sign of strong confidence in the
work they did.
So let's start by looking at how the
(08:46):
authors introduced the topic.
Apparently there has been a lot of
interest in studying the dark side of
personality.
specifically focused on dark triad
traits.
These traits are narcissism,
psychopathy, and Machiavellianism.
How are each of these defined?
Narcissism is characterized by a strong
drive for self-enhancement,
(09:07):
seeking admiration,
and recognition from the social
environment.
Huh.
That actually describes…
me.
Maybe it's the real reason for this
side.
Well, anyway, I knew this already,
(09:27):
although I do mostly counteract my
narcissism with self-deprecation.
So that's narcissism.
Let's look at Machiavellianism.
Machiavellianism is defined as a
strategy of social conduct that
involves manipulating others for
personal gain,
often at others' expense.
Okay,
now I need to state that even though I
(09:50):
may have manipulated some of you into
listening to this podcast,
as of this recording,
I have gained little other than my own
catharsis in this creative endeavor.
It's a money pit rather than a money
maker.
You're welcome.
Lastly, there is psychopathy.
Psychopathy is shaped by a persistent
(10:10):
disregard for social norms,
lack of empathy,
and an absence of remorse or guilt.
Okay, that's not me.
I don't think, anyway.
Now,
I can conceptualize that these traits
would be measurable.
Like,
you could probably do it with self-reported
feelings using a Likert scale.
(10:31):
The Likert scale, if you don't know,
is a scale that you see on surveys
where you answer on a scale of 1-5 or 1
-10 or strongly agree to strongly
disagree.
That's a Likert scale.
Anyway,
between that and behavioral observations,
I'm sure you could measure these well
-defined traits of narcissism,
psychopathy, and Machiavellianism.
(10:53):
And the authors state that these have
been studied quite a bit over the last
20 years.
They even point out that,
as studied in the work environment,
these traits,
when moderately displayed,
can have a somewhat positive outcome,
such as in leadership context.
Have you ever heard that most CEOs are
psychopaths?
(11:14):
I imagine this research is where that
comes from.
The other parts of this is that the
authors state that much of previous
research has focused on personality
traits being stable,
meaning that narcissism, psychopathy,
and Machiavellianism, and even,
I guess let's call it light-side
personality traits,
would be considered constant in these
(11:35):
studies.
Their argument is that more recent work
has looked at these personality traits
being more malleable,
and they may be influenced by other
factors.
So, if you ever meet someone that says,
people can change,
or that desperate girl that says,
I just feel like I can fix him." They
might be halfway right anyway,
(11:56):
but it might not be your influence that
changes the strength of a personality
trait in another person.
Instead, it may be their environment,
their work, and in this study,
perhaps their sleep quality.
This may be further supported by
research that suggests that self
-regulation is needed to suppress dark
personality trait tendencies.
(12:17):
When you are stressed, fatigued,
less attentive,
or if you lack the cognitive resources
due to a heavy cognitive load,
you're coping with stress,
you feel threatened,
or if you're hungry,
apparently it's more likely that these
dark traits will surface.
All of this sets up the first part to
(12:37):
how they did this study and the model
that they used.
Remember,
models don't tell you how things
actually work.
They conceptualize how things might
work and tell you the data points to
measure to determine relationships
between the variables.
This model,
called the strength model of self
-control,
was introduced by Baumeister and Newman
(12:58):
in 1994.
The model suggests that controlled,
willful action quickly consumes and
depletes inner resources resulting in
self-control failure,
and you must have rest and sleep to
replenish those resources of self
-control.
The authors presented previous research
that has linked a lack of sleep to
(13:20):
increases in irritability,
altered responses to frustration,
tendencies to blame other people for
problems, lowered empathy,
and lower distress tolerance.
So their first presented hypothesis is,
quote,
sleep quality and quantity are negatively
related to dark triad states at work.
(13:41):
Good.
That's measurable.
Basically,
that means that what they expect to
find is that an increase in sleep
quality and quantity will result in
lower prevalence.
of narcissism, psychopathy,
and Machiavellianism.
Of course,
the inverse would also be true,
if this was the case.
They also wanted to study this idea of
(14:02):
distress tolerance.
Individuals with low distress tolerance
are expected to report distress as
unbearable,
struggle to handle being distressed or
upset,
and increasingly use impulsive behaviors
to alleviate distress.
So their second hypothesis is, quote,
distress tolerance mediates the
(14:23):
negative relationship between sleep
quality and quantity on the one hand
and dark triad states on the other hand
in such a way that better sleep, i.e.
higher sleep quality and longer
sleeping hours,
relates to higher distress tolerance,
which in turn relates to less dark
triad state expressions.
(14:44):
Do you remember what mediation is?
Previously,
we talked about mediating and
moderating variables.
A mediating variable serves as the go
-between for two variables,
explaining how two variables are
related,
whereas a moderating variable affects
the strength and direction between two
variables.
So what the authors are hypothesizing
(15:06):
here is that distress tolerance
explains the negative relationship
between sleep and dark personality
traits.
So let's look at how they designed the
study.
The authors used a 10-day experience
sampling method among 103 employees
making 786 repeated observations.
(15:27):
The experience sampling method is a
research technique that involves
collecting data about individuals'
thoughts, feelings,
and behaviors in their natural
environments at multiple points in
time.
This is actually a good way to do this
and reduce what's called recall bias,
which is an error you can get when your
participants inaccurately or
incompletely remember their past
(15:48):
events.
So they recruited workers from one of
the authors' social networks,
so it's a convenience sample.
We've also talked about that before.
Sometimes you have to work with what
you have.
It makes the study less experimental as
far as sampling goes,
but there are plenty of ways to control
the bias and make the best of it.
(16:08):
Participants received two
questionnaires every day,
one in the morning where they were
asked to report on their sleep quantity
and quality,
and one in the afternoon where they
reported on their distress tolerance
and dark triad states of that workday.
Now already I can see where you could
probably strengthen the study a bit if
you gave them all sleep trackers and
(16:29):
got a more accurate score,
but I get that may not have been
feasible.
They did a pretty good job of data
cleanup here,
eliminating duplicate responses,
unmatched morning and afternoon
responses,
and observations where the afternoon
survey was completed before the morning
survey.
The final sample had 57 folks from
(16:50):
Belgium, 46 from Argentina,
average age was 42 years,
and pretty much half male and half
female.
The only statistically significant
differences they had between the groups
was that Belgian participants scored
higher on average distress tolerance
and Argentinian participants scored
higher on average dark triad states.
(17:11):
As I suspected,
they used the Likert scales to measure
sleep quality, distress tolerance,
narcissism, psychopathy,
and Machiavellianism.
The authors also talk about the power
of their sample.
Basically,
this is a statistical test you can use
to figure out how strong your sample
size is based on the number of
participants you have and the type of
(17:32):
statistical test you are using for your
correlation analysis.
They admit to having a small effect
size of 0.14.
For reference, the scale is 0 to 1,
with 1 being the largest effect size.
This doesn't mean that the results
don't mean anything,
it's just a way to say,
take this study for what it is with the
(17:53):
sample we had,
and we probably need to have a larger
sample size in the future to verify the
results.
They also used intraclass correlation
coefficient measurements to test the
reliability of multiple measurements of
the same variable.
Basically,
they found that a fairly high
percentage of the variation in the dark
triad, distress tolerance,
(18:14):
and sleep quality and quantity were due
to within-person variation in those
constructs.
Now, let's get to hypothesis testing.
They used a two-level regression model,
which is fantastic,
to test between dark triad states and
sleep quality and quantity.
They found that sleep quality and
(18:35):
quantity had a statistically
significant negative relationship with
the dark triad states.
Sleep quality and quantity accounted
for 74.6% of the variance in
Machiavellianism,
75% of the variance in psychopathy,
and 70.8% of the variance in
narcissism.
These are big numbers for accounting
(18:55):
for variance.
Additionally,
they did find that distress tolerance
effectively mediated this relationship.
Sleep quality statistically
significantly impacted distress
tolerance,
and distress tolerance statistically
significantly impacted the dark triad
states.
Same for sleep quantity.
(19:15):
However,
they noted that this was only a partial
mediation in both cases based on their
test results.
Now,
they also did some additional analyses,
which you can totally do if you already
have the data.
It's kind of a fuck it,
why not scenario.
I end up doing this all the time in my
own research.
Having the data sparks even more
(19:36):
curiosity.
One interesting point is that they
found participants with higher average
dark state levels,
meaning they probably display these
traits stronger anyway, had even...
stronger elevated dark state
expressions in response to poor sleep.
So if you are already naturally on the
dark side,
(19:56):
a bad night's sleep is only going to
exacerbate the problem and more so than
for anyone else.
The other test was for reciprocal
effects.
So instead of sleep affecting the dark
triad states,
how do dark triad states affect sleep?
Interestingly,
Machiavellianism predicted increased
(20:17):
sleep quality and quantity,
and narcissism negatively predicted
sleep quality and quantity.
However,
the calculated variance was very
minimal,
less than 5% for each of these.
So what are the practical implications
for this?
Well, first of all,
the authors state that these dark
personality traits can negatively
affect work performance and work
(20:38):
culture as supported by previous
research.
They also suggest that since sleep can
be influenced by many different
factors.
not just drugs,
they encourage employers to promote
healthy sleep habits.
And this isn't just telling your
employees, hey, go get some sleep.
For example,
they could limit overtime and shift
work,
(20:59):
provide flexible working arrangements,
establish policies that discourage
working more than a set number of hours
without rest,
and insistence on taking scheduled
breaks.
A sleep education could also be an
effective intervention.
The authors also bring up this idea of
allowing daytime napping at work,
although it's taboo in many workplaces.
(21:21):
I don't know.
Have you ever taken a nap during
working hours?
I'm not above admitting that I've done
it.
And even though I may work later
because I did,
I felt a lot more productive afterward,
perhaps a bit less narcissistic too.
All right, finally,
let's look at their limitations.
They talk about the limitations to
measuring sleep quality and quantity in
(21:42):
the way they did,
which they think they can mitigate by
capturing this metric closer to wake
time.
They also suggest wearable sleep
trackers would be more accurate,
which is exactly what I said earlier.
They said they could validate a new
instrument in the future,
which uses better phrasing to measure
the personality states,
also cultural differences in sleep and
(22:04):
napping habits between Belgium and
Argentina could have impacted the
results.
Another thing that wasn't measured is
the fact that even if someone has the
cognitive ability to suppress dark
tendencies,
they may still choose not to suppress
them.
And lastly,
they like to see the daytime napping
element explored better in the future.
(22:25):
So ultimately this was a very well
executed study, in my opinion.
It's hard to argue that a bad night's
sleep will negatively impact your day.
However,
this study put some numbers to sleep's
effect on your bad personality.
So the next time you run into someone
who's being a little too narcissistic
or or psychopathic,
(22:47):
just think about this.
It may not be about the side of the bed
they woke up on after all.
It may just be that they suck at
sleeping.
With that being said,
I'm gonna go take a nap.
I'm Dr.
Matt Law,
and this has been another great episode
of Study Finds on the Prove It To Me
podcast.
Take care and stay safe, everyone.
(23:10):
["Study Finds on the Prove It To Me"]
Prove It To Me is produced by me,
Matt Law,
original music by West London.
You can find this podcast on Podbean,
Apple Podcasts, Spotify, YouTube,
(23:32):
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Like what you've heard so far?
Please like, subscribe,
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Got questions about what we talked
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send an email to contact at proveitpod
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The views and opinions expressed in
(23:52):
this podcast are those of the host and
its guests and do not necessarily
represent the official position,
opinion,
or strategies of their employers or
companies.
Examples of research and data analysis
discussed within this podcast are only
examples.
They should not be utilized in the real
world as the only solution available as
they are based on very limited,
often single use case,
and sometimes dated information.
(24:13):
Assumptions made within this discussion
about research and data analyses are
not necessarily representative of the
position of the host, the guests,
or their employers or companies.
No part of this podcast may be
reproduced,
stored in a retrieval system,
or transmitted in any form or by any
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(24:34):
The presentation of the content by the
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