Introductory
waffle
This week’s blog post is a little different. In part, it is
a response to my students’ requests for a demonstration of the “critical
thinking” I keep demanding from them. Fair enough. It is important for people to be as clear as possible about what they mean when they use ‘technical’ words and phrases. Accordingly,
this post provides a partial critique of a recent paper relevant to this week
on my altruism module. That paper, by Meffert et al. (2013), has been widely reported
as showing that:
The central
claim
Meffert and her colleagues claim to demonstrate a need for “a
profound reconceptualization of psychopathy” (p. 2559). They note that psychopaths
are usually portrayed as having “a profound lack of empathy” (p.
2550) due to their deficient brains making them incapable of caring about others’ welfare. Against this, Meffert et al. (2013) claim to show
that, while psychopaths usually don’t care about others’ welfare, they can
do so when motivated to try.
See how I can force myself to share your joy at this stunning news!
The evidence
There are two main parts to Meffert et al.’s evidence.
The first they claim shows that, as commonly believed,
non-psychopaths typically have more pronounced reactions to others’ experiences
than do psychopaths. The second they claim shows that psychopaths and
non-psychopaths have (more) similar reactions to others’ experiences when each
is deliberately trying to empathise.
The samples
For key similarities and differences across groups to be
meaningfully interpreted it is important to know how comparable the groups are.
Meffert et al.’s paper does not make it easy to determine such things.
Almost nothing is said about who the control group were (e.g.,
members of the general public) or about how either the control group or the
psychopathic (“target”) group were recruited.
In the “Participants” section on p. 2551, the paper says
that the control participants were male and had the same handedness as members
the target sample. (Many neuroimaging studies exclude left-handed people.) It also says that the
target group and the control group had, on average, the same age and IQ. I could not find a report of how low or high that average IQ was.
Later in the paper, Meffert et al. reveal that the control
group also differed from the target group on a range of “factors linked to
criminal lifestyle (e.g., lower level of education, history of drug abuse and
length of incarceration)” (p. 2558).
Given this, attributing found differences between the target
and the control groups specifically to their differences in psychopathy levels
seems somewhat bold, especially if they could plausibly stem from other differences between the groups.
Generalisability
As just seen, the term “psychopaths” does not capture all
that was distinctive about Meffert’s target sample. As well as being diagnosed
as psychopathic, the eighteen members of that sample were also Dutch, adult,
male, poorly educated, right-handed, incarcerated criminals, the vast majority
of whom had a recognised dependence on drugs. It seems at best questionable
that this tiny and highly distinct sample is strongly representative of all
people high in psychopathy. Even most media headlines reporting the study took
care to be clear that the findings relate most obviously to criminal psychopaths.
Of course, if the study compellingly shows that any psychopaths
(perhaps especially criminal ones) can care about others’ welfare (perhaps especially
that of anonymous strangers), that may indeed suggest that a profound
reconceptualization of psychopathy is needed.
Confirmation
of a psychopathy difference across samples
To attribute other differences between the two groups to
their difference in psychopathy, one clearly needs to be pretty sure that there
are differences in psychopathy across groups. In Meffert et al.’s study members
of the target sample were all diagnosed as psychopaths and members of the
control group (as far as I can tell) were not. Nevertheless, it makes sense to
check and Meffert et al. did. All participants completed a 187-item self-report
measure of psychopathy (p. 2551).
As expected, the control group obtained a lower average
score on this Psychopathic Personality Inventory (PPI) than did the target
group: about 399 vs. 422 (Table 1, p. 2555), a statistically significant difference
(p < .05, p. 2554).
If I had more time I would examine this result a lot more
closely. Like many psychiatric diagnoses, “psychopathy” is somewhat an umbrella condition and two people or samples with identical scores might obtain those scores because of very different qualities. Moreover, Meffert’s control group psychoticism
score of 399 is much higher than the average score of 268 obtained by some very
scary criminals sampled in a study by Copestake et al. (2011).
For the sake of argument, though, let’s accept that Meffert
et al.’s target group members were psychopaths (among other things) and that their
control group members were not.
The “spontaneous
empathy” task
All participants watched short video clips of two hands
interacting. The hands interacted in several ways, two of which are more
important than the others. In the “love” interactions an “approaching” hand
stroked the back of someone else’s “receiving” hand, which gave a tender
squeeze in response. In the “pain” interactions the approaching hand pulled
back one of the receiving hand’s fingers to a point that would be painful for
most people.
Participants in this spontaneous empathy task were given the
rather strange instruction to view the film clips “as if they were watching one
of their favourite videos” (p. 2552). Call me strange but I’d find it quite
unsettling pretending that my favourite videos comprised largely of clips in
which people were inexplicably deliberately hurting others!
Initial
results
The two groups had differing brain activation in “a large
network of regions” (p. 2555). In each of these regions the control group
showed higher brain activation than did the psychopath group (Table 2 and Supplementary
eTable 2). Some of these Meffert et al. considered regions of particular interest
because past research suggests that they are sometimes similarly activated both by personal experience and by observation of others having similar experiences (p. 2553). These included “the dorsal and ventral premotor
cortex, primary
and secondary somatosensory cortices, the anterior
insula and the cingulate
cortex” (p. 2555).
Accepting for the sake of argument that these findings and the
authors’ interpretations of them are valid, “individuals with psychopathy
showed … reduced activation” compared to control participants in brain areas
associated with (among other things) vicarious experience, sensations, and emotions (p.
2558).
To report these results slightly differently, when
instructed to watch short clips of interacting hands as if they were watching their
favourite videos, poorly educated, incarcerated, drug-dependent, male criminals
with relatively high levels of psychopathy appeared not to react as emotionally
as did relatively well-educated, non-addicted, non-criminals with relatively
low levels of psychopathy.
Maybe this indicates a difference in spontaneous empathy and
maybe it results from a difference in levels of psychopathy across groups. Many
other possibilities seem at least plausible.
My guess is that members of the target group were less
motivated and anyway less able to comply with the task. I also doubt that this was
primarily due to differences in psychopathy.
It seems at least possible that the control group members were
more or less willing and able to comply with the instructions and they
accordingly became relatively engrossed in the task of trying to conceive of
the emotionally-evocative hand-theatre as high-drama. I suspect that the
uneducated, drug-addled, career criminals would have really struggled (if they
even tried) to successfully enter into the same spirit. If so, the brain
activation differences across groups stemmed from the different engagement in
the task due to different compliance with the viewing instructions, which
itself stemmed mainly from the factors that happened in this study to be
associated with psychopathy.
This is of course only my guess. The much more important
point is that there is no compelling evidence which enables anyone to choose
between my guess and Meffert et al.’s interpretation of their findings. The
first part of their study may or may not tell us anything about psychopathy and
if it does, there is no telling what, exactly. The two groups differed on too
many potentially important characteristics, the instructions given to
participants before the main task plausibly promoted different responses in
each group, and no checks were made for differences between the groups in such
things as task-engagement (e.g., how much participants tried and succeeded in
viewing the clips as though they were their favourite movies), task-accuracy (i.e., how well each group recognised the emotional content of the viewed
videos), subjective experience during the task (e.g., how emotionally aroused
participants felt and what specific emotions were involved), or how they felt “on
behalf of” the hands/people in the video clips (e.g., "empathic" joy, distress, anger,
etc.).
In some ways, perhaps it doesn’t matter. In this part of the
study, Meffert et al. are pushing at an open door. As they note themselves, the
claim that psychopaths empathise less with others’ experiences than do
non-psychopaths is the standard view – as well it might be because having a
lack of empathy is part of the diagnosis for being a psychopath!
Let us therefore move on the second strand of evidence
considered by Meffert et al.
The “deliberate
empathy” task
Participants next watched a slightly different series of
hand-interaction video clips, some showing nothing but “loving” interactions
and some showing nothing but “painful” interactions. This time, participants received
instructions to “feel with” one or other of the hands.
In this task, there were still many differences in brain
activation across the groups (Supplementary eTable 3) but (a) it varied which
group had the higher level of activation in a given area, (b) almost none of
the areas of differential activation occurred within the researchers’ identified
regions of interest (Table 3), and (c) there was less difference in brain
activity between the target and control groups than had been the case in the
“spontaneous empathy” condition.
Thus, in brain areas relevant to having similar experiences
to those others seem to be having, psychopaths were not that different
to non-psychopaths during this “deliberate empathy” task. The authors conclude that psychopaths are almost as able to
experience vicarious emotions as non-psychopaths when each is “following
instructions to empathize”.
Let’s phrase this conclusion a little more conservatively. If
valid, this part of Meffert et al.’s study finds relatively little difference
in brain activation when (druggy, criminal, etc.) psychopaths and (non-druggy,
non-criminal, etc.) non-psychopaths are instructed to “feel with” someone
else’s hand which is giving or receiving either a loving caress or a painful
smack with a ruler.
Meffert et al. provide one possible explanation for this,
i.e., that all participants were feeling love or pain as though they
were actually experiencing caresses or smacks themselves. Another possibility
is that no one was feeling very much, in either group. No measure was
used to check this either way.
Being asked to “feel with” a hand that one is watching on a
video is an odd instruction. Imagine being a participant in this study
yourself. If you were told to “feel with” a videoed hand hitting someone else’s
hand with a ruler, do you imagine that it would feel like your hand was
swooshing down and reverberating with the shock of contact? Or do you imagine
that you would try to work out what sorts of experiences an owner of such
a hand might be having, perhaps by imagining how you might feel in such a
situation? If like me you find the ‘working out’ possibility plausible, it
seems at least possible that both groups were engaging in quite a lot of thinking
about others’ feelings – without necessarily having comparable
(“vicarious”) feelings themselves.
Such a possibility may seem particularly credible when we
learn that during this task the target group had relatively high activity in
“mentalising” areas of the brain, i.e., those thought to be involved when
trying to work out what others are experiencing (p. 2559). It is widely acknowledged that psychopaths can be good at identifying others’emotions, all the better to exploit them for personal gain.
As in the first part of the study, Meffert et al. do too
little to work out what participants in each condition are doing and
experiencing to be confident about how best to interpret the differences in the
brain activation they find – still less the differences they don’t find.
Conclusion
The most important of Meffert et al.’s findings for their
key claim is that uneducated, criminal, drug-addicted psychopaths and educated,
non-criminal, non-addicted, non-psychopaths show relatively similar levels of activation
in brain regions associated with vicarious emotions when instructed to “feel
with” one or other hand in short videos of hands interacting in apparently
loving or painful ways.
One possible reason for this is that the uneducated, criminal,
addicted psychopaths had subjective experiences that corresponded in
some way to those portrayed in the videos (to about the same extent that anyone
else would) and one possible and scientifically dramatic implication of this is
that psychopaths can care about the welfare of others when they choose
to do so.
Another possibility is that, regardless of levels of
psychopathy, all participants in this part of the study were trying to work
out what experiences others might be having and this did not markedly
involve anyone actually having “vicarious” feelings (or being concerned
about the welfare of anyone else having similar feelings). This possibility
would do nothing whatsoever to threaten standard conceptions of psychopathy.
Given the multiple impediments to confidently interpreting
Meffert et al.’s results, much more and much better evidence is needed before
there is good reason to suppose that psychopaths are able to share or truly
care about others’ emotional experiences.
Caveats
Meffert et al. (2013) is much more complicated than I
have let on here. I am not a neuropsychologist and I am not familiar with many
of the methodological and statistical procedures reported in Meffert (2013).
This means that you should be particularly sceptical of any of my claims above
which might be hindered by these inadequacies on my part. On the other hand,
there are problems with the paper that, because of time and presentation issues,
I did not make explicit here (e.g., the potentially rather suspect practice of
comparing brain activation in the “spontaneous” and the “deliberate” empathy
parts of the study) and there may be other – perhaps more serious – problems
with the paper that I am simply not skilled enough to notice. If anyone would
like to correct my claims or make new ones in the comments section below, your
contribution to my and my students’ education will be most welcome.
References and
further reading
Chambers, C.
(2013, Nov 25). Could a brain scan diagnose you as a psychopath? The Guardian
[Link]
Copestake,
S., Gray, N. S., & Snowden, R. J. (2011). A comparison of a
self-report measure of psychopathy with the psychopathy checklist-revised in a
UK sample of offenders. Journal of Forensic Psychiatry & Psychology 22(2):
169–182.
Jarrett, C.
(2013, Dec 13). A calm look at the most hyped concept in neuroscience – Mirror neurons.
Wired. [Link]
Jarrett, C.
(2012, Dec 10). Mirror neurons: The most hyped concept in neuroscience? Psychology Today [Link]
Lamm, C.,
& Majdandžić, J. (2014). The role of shared neural activations, mirror
neurons, and morality in empathy-a critical comment. Neuroscience
Research. [Link]
Neuroskeptic
(2014, July 21). Functional neuroimaging’s Neymar problem. Discover. [Link]
Neuroskeptic
(2014, June 6). fMRI motion correction: The quick and the dead. Discover. [Link]
Neuroskeptic
(2013, May 13). Looking Askance At Cognitive Neuroscience. Discover. [Link]
Neuroskeptic
(2013, April 27). The (sigh) psychopath brain. Discover. [Link]
Neuroskeptic
(2012, April 25). Does brain scanning show just the tip of the iceberg? Discover. [Link]
Neuroskeptic
(2009, Sept 16). fMRI gets slap in the face with a dead fish. Discover. [Link]
Vincent, J.
(2013, July 26). An 'empathy switch' allows psychopaths to feel at will. Discover. The Independent. [Link]
Wikihow. How to identify a psychopath. [Link]
Picture credits
Psychotic empathy doll [Link]
Forced smile [Link]
Sherlock Holmes [Link]
Snakes in suits [Link]
How to cite this
blog post using APA Style
T.
Farsides. (2014, November 17). Psychopathic empathy. Retrieved from http://tomfarsides.blogspot.com/2014/11/psychopathic-empathy.html
No comments:
Post a Comment