The Stigma(s) of Mental Illness

Fighting "the stigma of mental illness" is big business at the moment. But does "the stigma" really exist?

As I said back in 2010 :

There is a stigma of schizophrenia, and there's a stigma of depression, etc. but they're not the same stigma. We're told it's a myth that "the mentally ill are violent" - [but] no-one thinks depressed or anorexic people are violent. They think (roughly) that people with psychosis are. They have other equally silly opinions about each diagnosis, but there's no monolithic "stigma of mental illness".

Now a paper has come out which explores this idea in some detail: Stereotypes of mental disorders differ in competence and warmth. The title says it all : people have stereotypical views of people suffering from different mental disorders, but these stereotypes vary substantially.

The authors use the "Stereotype Content Model" framework, which despite the fancy name is very simple. On this view stereotypes are characterised by two dimensions, "competence" and "warmth". These are pretty self-explanatory. Warmth is whether you're seen as nice and friendly, or hostile and dangerous. Competence is whether you're thought to be good at it.

We all know that warmth and competence are distinct and indeed orthogonal concepts, and they crop up in other languages and in popular culture.

Anyway, in two Mechanical Turk online surveys of American adults, they first showed that respondants felt that "people with mental illness" were low on competence and (slightly) low on warmth, compared to other social and ethnic groups. That's similar to the ratings of the homeless, poor, and welfare recipients.

However in the second study, they asked about specific diagnoses, and this revealed a more complex pattern. I've shown the results above (colors are mine). There seemed to be four clusters. Mental retardation and Alzheimer's were perceived as warm, but incompetent; sociopaths and violent criminals were the opposite.

Schizophrenia clustered with homelessness and addiction in a worst-of-both-worlds category of low warmth and competence, while what could broadly be called "emotional" disorders, like bipolar, depression and anxiety, were rated more favorably. For what its worth, OCD was the least bad diagnosis.

These are interesting results. The only oddity about the method was that people weren't actually asked what they thought about these people; they were asked “In general, how much do Americans believe that..." This is, apparantly, standard procedure in this kind of stereotype research, but it seems a little strange to me.

Sadler, M., Meagor, E., and Kaye, K. (2012). Stereotypes of mental disorders differ in competence and warmth Social Science and Medicine DOI: 10.1016/j.socscimed.2011.12.019

A Correction

In my previous post, on the paper A Facial Attractiveness Account of Gender Asymmetries in Interracial Marriage by Michael B. Lewis, I wrongly stated that it was unclear from the paper whether the research assistant who selected the Facebook images was blind to the hypothesis of the study.

In fact, the paper did state that they were "a naive research assistant", something I missed. Apologies for this avoidable mistake. I've corrected the post.

I'd also like to take this opportunity to remind everyone that sometimes comments will get caught in the Blogger spam filter, especially if they're long or contain links, but it can happen to any comment. If your comment doesn't appear immediately, don't worry, I will manually approve such comments as soon as possible.
 
Lewis, M. (2012). A Facial Attractiveness Account of Gender Asymmetries in Interracial Marriage PLoS ONE, 7 (2) DOI: 10.1371/journal.pone.0031703

The Evolutionary Psychology of Race, Beauty and Marriage

There are some papers that you can tell are going to be hot potatoes just from the titles. This is one of them: A Facial Attractiveness Account of Gender Asymmetries in Interracial Marriage.

Coming so soon after The Unconquered World, you'd be forgiven for thinking I am taking this blog in a more linkbaiting direction because I'm planning to introduce ads. I'm really not, it's just a coincidence.

The paper claims that white women are on average more attractive than black, while East Asians are prettier still.  For men, however, the positions were reversed (and the effects were even stronger.)

Saying that black women are on average less attractive than others was what got evolutionary psychologist and blogger Satoshi Kanazawa into spot of bother last year. The current paper agrees with Kanazawa on that point (though doesn't cite him)... although it also declares Kanazawa to be part of the least attractive race for males, so I don't know how happy he'll be about it.

Author Michael B. Lewis of Cardiff University took 600 Facebook photos "from people who were members of groups associated with further and higher education bodies either in the UK (for White faces), sub-Saharan Africa (for Black faces) and East Asia (for Asian faces)."

Photos with a "weird expression" and people who "looked" under 18 or over 30 were excluded. The actual ages were not checked. Hmm.

A panel of 40 British students (half male) were asked to rate all of the opposite-sex faces for attractiveness from 1 to 10. The ethnicity of the rater made no difference to the results but there were only 5 black and 6 Asian students out of 40 though:

After this we get some models proposing how these data might relate to British and American inter-racial marriage patterns, and some evolutionary speculation regarding why this might have evolved - Asia was cold so men were in short supply, that kind of thing - but that's all assuming the basic data are solid.

There are many possible objections to the methodology here, some of which are addressed in the paper, but there's one massive that isn't -

It's not stated how the Facebook images were gathered. All we're told is that "a research assistant" got the images from higher education institutions. Were they, consciously or subconsciously, picking photos that fitted the expected some pattern?

We're not told whether or not this individual was aware of the hypothesis of the study when they chose the pics. If they were aware, it's a fatal confound; (Edit - 19th Feb 2012 - The paper in fact says that the research assistant was "naive" i.e. that they were not aware of the hypothesis of the study, which is of course sound methodology. I missed this statement in the first version of this post.)

However, the broader point remains that they might have been selecting in line with their own preferences, or some other bias. Clearly, there's much room for cherry picking the examples, based on whether they "looked" too young or old, or had a "weird" expression...

Link: Also blogged about here.

Lewis, M. (2012). A Facial Attractiveness Account of Gender Asymmetries in Interracial Marriage PLoS ONE, 7 (2) DOI: 10.1371/journal.pone.0031703

The Unconquered World

A thought struck me the other day: China is the only place in the world that has never been controlled by a European power, whether as a colony, protectorate, territory, mandate, etc.

Thinking about it a bit more I realized this is not quite true, but it's not far off. As far as I can tell (thanks Wikipedia) the following countries were never officially under European control. I'm including the USA, Australia, New Zealand and the USSR as "European". Note that I use the modern names of countries to refer to the territory that falls within their borders, even though it wasn't always called that.

Most of China
Thailand
Mongolia
Saudi Arabia (assuming the Ottoman Empire was not a "European power")
Bhutan
Nepal

Iran and Turkey make the list, unless you count Alexander the Great.

Japan and North and South Korea make the list unless you count the post-WW2 occupations.

All of these areas were under various forms of influence at different times, but they never formally lost their sovereignty to Europe. (Edit: Iran and Turkey removed because they were conquered by Alexander.) (Edit 2: Added Bhutan and Nepal which I missed before. Changed map to show special status of Japan, Korea, Turkey & Iran).

Disclaimer: I'm not a geographer; this is something I put together purely out of interest. It's quite likely that I've missed some. In particular I don't know anything about the small island nations. Please comment if you can correct this, it's a work in progress.

Tired Brains Are More Excitable

An important new study shows how being awake causes progressive changes to the brain. This could shed light on the function of sleep - but it also raises warnings for neuroscientists.

Italian researchers Huber et al report that Human Cortical Excitability Increases with Time Awake. The experiment was conceptually simple - they measured cortical excitability when people were well rested and then looked to see how it changed as they were kept awake for over 24 hours.

The participants woke up at 7 am on Day 1 and were kept awake all of that day, all of the subsequent night, and all of Day 2. The excitability measurements spanned a period of 30 hours, from 9 am to 3 pm the next day. They were finally allowed to go to sleep on the next night and one final session took place on Day 3. I hope they got well paid for taking part.

The results showed a nice linear increase in excitability with increasing time spent awake. Sleep put this back to normal - mostly:

"Excitability" was measured using electroencephalography (EEG) combined with transcranial magnetic stimulation (TMS). Essentially, they zapped the brain (left frontal cortex) with a strong magnetic pulse, and measured the electrical activity that this provoked in the brain.

It was a small study but the findings look solid, with all six participants showing clearly higher stimulation-evoked potentials after sleep deprivation. EEG cortical theta band activity was also correlated with time spent awake, replicating previous findings.

The authors say that these data fit with the idea that the function of sleep is to prevent the brain from becoming too excitable. I previously described this as the "defragmentation" hypothesis of sleep.

The theory goes that while we're awake, our brains are constantly forming new and stronger synaptic connections, as we learn and remember. Most of the new connections are excitatory. However this creates a problem because the brain must maintain a delicate balance between excitation and inhibition. Too much neural excitation and you'll have a seizure, amongst other things. So some researchers believe that during sleep, the brain "prunes" the new excitatory connections in such a way that the information they store is preserved, but the overall excitability is reset.

These data are the first clear-cut human evidence in favor of the theory. Most of the previous work was in animals.

So sleep researchers will be very interested by this paper, but all neuroscientists should take note. If being awake changes cortical excitability, it means that the time of day that you conduct your experiments could have an impact on your results. EEG researchers should pay particular notice, but it could well be that these changes also affect the fMRI signal.

This could be a serious confounding factor in your data. Suppose, for example, that your healthy controls are more likely to have jobs than your patients with, say, autism or depression - which is sadly all too common. Now people with jobs would naturally prefer to attend your study later in the day, after work, leaving those with more flexible schedules to come in bright and early... you see the problem.

Huber, R., Maki, H., Rosanova, M., Casarotto, S., Canali, P., Casali, A., Tononi, G., and Massimini, M. (2012). Human Cortical Excitability Increases with Time Awake Cerebral Cortex DOI: 10.1093/cercor/bhs014