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Diametrical Model Of Autism And Schizophrenia

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One interesting thing I took from Evolutionary Psychopathology was a better understanding of the diametrical theory of the social brain.

There’s been a lot of discussion over whether schizophrenia is somehow the “opposite” of autism. Many of the genes that increase risk of autism decrease risk of schizophrenia, and vice versa. Autists have a smaller-than-normal corpus callosum; schizophrenics have a larger-than-normal one. Schizophrenics smoke so often that some researchers believe they have some kind of nicotine deficiency; autists have unusually low smoking rates. Schizophrenics are more susceptible to the rubber hand illusion and have weaker self-other boundaries in general; autists seem less susceptible and have stronger self-other boundaries. Autists can be pathologically rational but tend to be uncreative; schizophrenics can be pathologically creative but tend to be irrational. The list goes on.

I’ve previously been skeptical of this kind of thinking because there are many things that autists and schizophrenics have in common, many autistics who seem a bit schizophrenic, many schizophrenics who seem a bit autistic, and many risk factors shared by both conditions. But Del Giudice, building on work by Badcock and Crespi presents the “diametrical model”: schizophrenia and autism are the failure modes of opposing sides of a spectrum from high functioning schizotypy to high functioning autism, ie from overly mentalistic cognition to overly mechanistic cognition.

Schizotypy is a combination of traits that psychologists have discovered often go together. It’s classified as a personality disorder in the DSM. But don’t get too caught up on that term – it’s a disorder in the same sense as narcissistic or antisocial tendencies, and like those conditions, some schizotypals do very well for themselves. Classic schizotypal traits include tendency toward superstition, disorganized communication, and nonconformity (if it sounds kind of like “schizophrenia lite”, that’s not really a coincidence).

Typically schizotypals are supposed to be paranoid and reclusive, the same as schizophrenics. But the diametrical model tries to downplay this in favor of noting that some schizotypals are unusually charismatic and socially successful. I am not exactly sure where they’re getting this from, but I cannot deny knowing several extremely charismatic people with a lot of schizotypal traits. Sometimes these people end up as “cult leaders” – not necessarily literally, but occupying that same niche of strange people who others are drawn toward for their unusually confident and otherworldly nature. Some of the people I know in this category have schizophrenic first-degree relatives, meaning they’re probably pretty loaded with schizotypal genes.

Schizotypals, according to the theory, have overly mentalistic cognition. Their brains are hard-wired for thinking in ways that help them understand minds and social interactions. When this succeeds, it looks like an almost magical understanding into what other people are secretly thinking, what their agendas are, and how to manipulate them. When it fails, it fails as animism and anthropomorphism: “I wonder what the universe is trying to tell me by making it rain today”. Or it fails as paranoia through oversensitivity to social cues: “I just saw him twitch his eye muscle slightly, which can sometimes mean he’s not interested in what I’m saying, and in the local status game that could mean that he doesn’t think I’m important enough, and that implies he might think he’s better than me and I’m expendable…”

Autism, then, would be the opposite of this. It’s overly mechanistic cognition, thinking in terms of straightforward logic and the rules of the physical world. Autistic people don’t make the mistake of thinking the universe is secretly trying to tell them something. On the other hand, after several times trying to invite a slightly autistic woman I had a crush on to things, telling her how much I liked her, petting her hair, etc, she still hadn’t figured out I was trying to date her until I said explicitly “I AM TRYING TO DATE YOU”. So not believing that you are secretly being told things has both upsides and downsides.

Autistic people are sometimes accused of looking for a set of rules that will help them understand people, or the secret cheat code that will make people give them what they want. I imagine an autistic person asking something like “What is the alternative?” This is the kind of thought process that usually works on stuff: figure out the rules that govern something, find a way to exploit them, and boom, you’ve landed a rocket on the moon. How are they supposed to know that human interaction is a bizarre set of layered partial-information games that you’re supposed to solve by looking at someone’s eye muscle twitches and concluding they’re going to steamroll over you to get a promotion at work?

Is this true? There’s…not great evidence for it. I’ve never seen any studies. There’s certainly a stereotype that brilliant engineers are not necessarily the most socially graceful people. But I know a lot of people who combine excellent technical skills with excellent social skills, and other people who are failures in both areas. So probably the best that can be said about this theory is that it would be a really neat way to explain the patterns of similarities and differences between schizophrenia and autism.

In this theory, both high-functioning autism (being good at mechanistic cognition) and high-functioning schizotypy (being good at mentalistic cognition) may be good things to have. But the higher your mutational load is – the less healthy your brain, and the fewer resources it has to bring to the problem – the less well it is able to control these powerful abilities. A schizotypal brain that cannot keep its mentalistic cognition yoked to reality dissolves into schizophrenia, completely losing the boundary between Self and Other into a giant animistic universe of universal significance and undifferentiated Mind. An autistic brain that cannot handle the weight of its mechanistic cognition becomes unable to do even the most basic mental tasks like identify and cope with its own emotions. And because in practice we’re talking about shifts in the complicated computational parameters that determine our thoughts and personalities, rather than the thoughts and personalities directly, both of these conditions have a host of related sensory and cognitive symptoms that aren’t quite directly related.

So here the reason why autism and schizophrenia seem both opposite and similar to each other is because they’re opposite (in the sense of being at two ends of a spectrum), and similar (in the sense that the same failure mode of high mutational load and low “mental resources” will cause both).

If you’re thinking “it sounds like someone should do a principal components analysis on this”, then Science has your back (paper, popular article). They find that:

Consistent with previous research, autistic features were positively associated with several schizotypal features, with the most overlap occurring between interpersonal schizotypy and autistic social and communication phenotypes. The first component of a principal components analysis (PCA) of subscale scores reflected these positive correlations, and suggested the presence of an axis (PC1) representing general social interest and aptitude. By contrast, the second principal component (PC2) exhibited a pattern of positive and negative loadings indicative of an axis from autism to positive schizotypy, such that positive schizotypal features loaded in the opposite direction to core autistic features.

In keeping with this theory, studies find that first-degree relatives of autists have higher mechanistic cognition, and first-degree relatives of schizophrenics have higher mentalistic cognition and schizotypy. Autists’ relatives tend to have higher spatial compared to verbal intelligence, versus schizophrenics’ relatives who tend to have higher verbal compared to spatial intelligence. High-functioning schizotypals and high-functioning autists have normal (or high) IQs, no unusual number of fetal or early childhood traumas, and the usual amount of bodily symmetry; low-functioning autists and schizophrenics have low IQs, increased history of fetal and early childhood trauams, and increased bodily asymmetry indicative of mutational load.

If men have much more autism than women, shouldn’t women have much more schizophrenia than men. You’d think so, but actually men have more. But men have greater variability in general, which means they’re probably more likely to satisfy the high mutational load criterion. So maybe we should instead predict that women should have higher levels of high-functioning schizotypy. Studies show women do have more “positive schizotypy”, the sort being discussed here, but lower “negative schizotypy”, a sort linked to the negative symptoms of schizophrenia.)

Something that bothered me while I was writing this: famous mathematician John Nash was schizophrenic. Isn’t that kind of weird if schizophrenia is about an imbalance in favor of verbal/personal and against logical/mathematical thinking?

There are exceptions to everything, and we probably shouldn’t make too much of one case. But I find it striking that Nash’s work was in game theory: essentially a formalization of social thinking, and centered around the sort of paranoid social thinking of figuring out what to do about how other people might be out to get you. This is probably just a coincidence, but it’s pretty funny.

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nikolap
17 days ago
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Zagreb, Croatia
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10/12/18 PHD comic: 'Glib'

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Piled Higher & Deeper by Jorge Cham
www.phdcomics.com
Click on the title below to read the comic
title: "Glib" - originally published 10/12/2018

For the latest news in PHD Comics, CLICK HERE!

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nikolap
99 days ago
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jlvanderzwan
99 days ago
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Sometimes I want to blame it all on Mitch McConnel, or Roger Ailes (see below), but then I remember that the Great Man theory is pretty strongly disputed these days.

https://www.rollingstone.com/politics/politics-news/how-roger-ailes-built-the-fox-news-fear-factory-244652/

Orthodoxxed!

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Even where they exist as departments, fields like gender studies are less institutionalized, more poorly-resourced, and more disadvantaged in hiring, promotion, and funding compared to mainline counterparts like psychology—doubly disadvantaged in the case of even newer fields like fat studies, also targeted in the hoax. They also tend to employ more women, people of color, and LGBTQ people, whose individual marginalization is compounded by the structure of academic institutions. The low impact factor of most of the journals that published the hoaxers’ papers testifies not just to the barrel-scraping to which they were reduced when more prestigious journals rejected them, but also to the struggle their fields face in the broader academic community. This is to be lamented, not celebrated, for these fields do in fact produce valuable and effective scholarship.
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nikolap
108 days ago
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"As historians and philosophers of science have long recognized, claims that good science is apolitical are routinely deployed in the service of very political ends."
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Actually, DMARC works fine with mailing lists

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There’s a common belief online that DMARC, an anti-phishing technology, prevents the proper operation of electronic mailing lists. To get around the perceived problem, many articles advise reconfiguring listserv software in ways that break the norms of SMTP.

However there is a configuration that allows mailing lists to work perfectly and still be able to relay messages in the presence of DMARC. Before describing it, let’s get some terminology straight.

Terminology and Basics

RFC5321.MailFrom
(A.k.a. return-path.) A record in an SMTP message’s “envelope,” saying whom to contact in the event of delivery failure. Emails can travel in multiple hops, being relayed from server to server, before reaching their destination. During transit, the RFC5321.MailFrom header contains an email address for the server that sent the message along the current hop.
RFC5322.From
A header inside the message itself, hopefully preserved across hops. This is the “From” field that email clients display, and it is supposed to be the email address of the person responsible for the email.
Sender
A less commonly known email header which indicates an intermediary who writes or sends a message on behalf of someone else. RFC 5322 gives the example of a secretary (Sender) who writes and sends a message on behalf of the boss (From).
SPF
Sender Policy Framework. A TXT DNS record which publishes the addresses of mail servers who are allowed to send or relay messages for a (sub)domain. Receiving mail servers can inspect RFC5321.MailFrom and bounce the message if it doesn’t match the servers listed in the SPF record.
DKIM
DomainKeys Identified Mail. DKIM are TXT DNS records which each contain a public key that is permitted to cryptographically sign the body, and a list of which email headers should be covered in the signature. Sending servers must know the private key in order to sign outgoing mail, and receiving mail servers can check the email against the public key to make sure it passes. This ensures that only authorized servers can originate mail for a domain, and also that relay servers cannot modify the message.
DMARC
Domain-based Message Authentication, Reporting and Conformance. A TXT DNS record which publishes a domain’s policy for how receiving mail servers should act on SPF or DKIM failure. Actions include ignoring the problem, sending the message to the spam folder, or outright bouncing the message. The DMARC record contains some other settings such as an email address for mail servers to report any non-conforming mail they receive.
Mailing list
A relay mail server which hosts a special address called a reflector. The mailing list relays any message sent to its reflector to the addresses of list subscribers. Mailing lists are used for group discussions, including collaborative software development.

While earlier methods such as PGP have existed to unmask mail forgery, DMARC has become the popular choice and is honored today on all major mail servers. However people whose domains employ DMARC are unable to send messages through traditionally-configured mailing lists. During DMARC adoption on major domains such as gmail and yahoo, mailing lists started having widespread problems.

Some people called DMARC a broken standard. They failed to implement elegant adjustments to mailing list behavior, and used hacky workarounds to fix the problem instead.

Let’s examine how a message passes or fails DMARC, and then learn how to fix lists. A message passes if either SPF or DKIM passes, and only fails if both SPF and DKIM fail. This way SPF-only and DKIM-only messages can pass DMARC, but messages without either SPF/DKIM will always fail.

Secondly, the message must pass “DMARC alignment.” Alignment means two different things:

  1. For SPF, it means that RFC5321.MailFrom == RFC5322.From
  2. For DKIM, it means that the message has one valid DKIM signature with “d=RFC5322.From”.
(Visualization of DMARC alignment from a Dmarcian article):
illustration of dmarc alignment

Fixing list behavior

If DKIM is not used

A mailing list is going to have a hard time relaying messages for any domain that uses DMARC and SPF but not DKIM. Consider this message:

Return-Path: <bounce@dmarcdomain.com>
From: "Sally Sender" <sender@dmarcdomain.com>
To: "Fun List" <fun@mailinglist.org>
Subject: Hi

Hi everyone

This would ordinarily be a proper reflection to a subscriber:

Return-Path: <fun-bounce@mailinglist.org>
From: "Sally Sender" <sender@dmarcdomain.com>
Sender: "Fun List" <fun@mailinglist.org>
To: "Roger Reader" <reader@destination.com>
Subject: Hi

Hi everyone

However destination.com will reject this message if mailinglist.org is not in the SPF record for dmarcdomain.com. Furthermore a good SPF record is not enough, since the Return-Path and From are out of alignment (they specify different domains).

Dealing with this situation is what causes the hacky workarounds. Lists have to use techniques like From-munging or MIME message wrapping to get the mail through.

Here is what From-munging looks like:

Return-Path: <fun-bounce@mailinglist.org>
From: "Sally Sender via Fun List" <fun@mailinglist.org>
Reply-To: "Sally Sender" <sender@demarcdomain.com>
To: "Roger Reader" <reader@destination.com>
Subject: Hi

Hi everyone

The recipient would only have to check DMARC for mailinglist.org which would pass. However this is a poor use of email, since it’s misrepresenting who originated the message. Also email clients often have a degraded interface with respect to the Reply-To header. It’s usually not visible in the message list, not used for sorting, and not added to the address book.

If DKIM is used

If the sending domain uses DKIM, it avoids the need for From-munging or other hacks. It works under the condition that the list does not modify the message.

Consider the properly reflected message again:

Return-Path: <fun-bounce@mailinglist.org>
From: "Sally Sender" <sender@dmarcdomain.com>
Sender: "Fun List" <fun@mailinglist.org>
To: "Roger Reader" <reader@destination.com>
Subject: Hi

Hi everyone

SPF will fail, as we saw earlier, so DMARC will try a DKIM check. The From, Subject and body were not modified so they will be properly signed. DKIM checks alignment between RFC5322.From and the signature’s domain, which will also match. DKIM passes, and message gets delivered.

Should be perfect, right? Well it could be, except lists traditionally add extra information in the subject and body of relayed messages, and the modified fields don’t pass a DKIM check. Messages from traditional mailing lists typically look more like this:

Return-Path: <fun-bounce@mailinglist.org>
From: "Sally Sender" <sender@dmarcdomain.com>
Sender: "Fun List" <fun@mailinglist.org>
To: "Roger Reader" <reader@destination.com>
Subject: [fun] Hi

Hi everyone

--
You are subscribed to the fun list, to unsubscribe
visit https://mailinglist.org/unsub/123

The subject line tag is typically used to sort the messages into a separate mailbox following user-defined rules in the email client. The unsubscribe link in the body is a convenience (and avoids government fines from violating the CAN-SPAM act.)

We need to give the client a way to sort mail, unsubscribe, etc without modifying the parts of the message signed by DKIM. Fortunately, there are RFCs for this. RFC2369 from 1998 and RFC2919 from 2001 both predate the DMARC machinery. The first introduces header fields for list information and control.

For our example RFC2369 allows us to add List-Unsubscribe: <https://mailinglist.org/unsub/123>. It also introduces headers like List-Help, List-Subscribe, List-Post, List-Owner, and List-Archive. What’s more, many mail clients understand these headers. Gmail adds an unsubscribe button to the web interface when it detects List-Unsubscribe.

The second RFC offers a way to identify a list with another header, like List-Id: The Fun List <fun.mailinglist.org>. Mail client rules can query this header rather than checking whether the subject field contains [fun].

Recommendation

It is reasonable nowadays to require that mailing list users whose domains use DMARC also enable DKIM. In fact the list software could check the sender’s domain at subscription time and raise an error if their domain uses DMARC but not DKIM.

Lists should keep the From address, the Subject, and the Message totally unchanged. They should add a Sender header to indicate their relay role, and set at least the List-Id and List-Unsubscribe headers for mailbox rules and subscription management.

This configuration will allow mailing lists to function as proper SMTP citizens in the age of DMARC.

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nikolap
127 days ago
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Zagreb, Croatia
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Puzzles about College

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Universities ostensibly aim to promote learning and critical thinking. This is one reason I wanted to become a professor—I share that aim. And this seems to be what most college professors believe too. It’s easy to be cynical. But, in my experience, most professors really do conceive of themselves this way: as purveyors of knowledge and learning.

But, if that’s truly a major aim of universities, then many things about the academy don’t make any sense. I’ve been living in the Ivory Tower for about 20 years now. I’ve seen many different universities over that time. Here are some of the puzzles that I’ve observed:

No background in the learning sciences. There’s a vast literature in educational and cognitive psychology on how we learn and how to effectively teach. While some of this is dreck, certain techniques are well-replicated and highly effective. But, as far as I can tell, most professors know little about this literature. Universities certainly don’t require that professors know anything about empirically-grounded techniques for teaching. It’s hard to make sense of this if a goal of universities is to promote learning. To take an analogy, it would be pretty strange if psychologists knew little about the evidence on how to effectively treat patients—or were never required to learn even a little bit about this.

Assessment of teaching. This knowledge deficit might not be a problem if you could learn effective teaching on the job. Maybe professors don’t need to know about the learning sciences if they could pick up the basics through trial and error. And I think you can—if your feedback mechanism is reliable. But, in my experience, the main mechanism of evaluation and feedback is student evaluations. There’s now excellent evidence that student evaluations have at best a weak relationship with effective teaching. In fact, some studies find that student ratings are negatively associated with learning. So, if that’s your main feedback mechanism, more experience won’t necessarily make you a better teacher.

And most universities seem pretty uninterested in more rigorous ways of evaluating student learning. A personal example: in all my time teaching, no one has ever suggested to me that I try to measure student learning with an externally validated pre-test/post-test. I never even heard of this until I started reading educational research.

Teaching skills. Here’s a piece of educational commonsense: if you want students to learn X, you should teach X, not Y. Take writing, critical thinking, or oral communication. Colleges say that they teach these skills. But, if you want to teach these skills, then you should teach these skills. It’s pretty strange to teach something that’s unrelated, like English literature or political philosophy, in the hopes that students will pick up these skills indirectly. But, as far as I can tell, most classes don’t actually teach skills directly. They instead teach fairly narrow content that most students rapidly forget (or never learn!).

Research. At most top universities and even liberal arts colleges, research is king. To get promoted, you can be a so-so teacher but you must be an excellent researcher. Quick question: why? I have some pretty good hypotheses about what explains most of the above, but this one kind of stumps me. It would be one thing if most research was socially valuable. But, try as I might, that’s hard for me to believe. Let me pick on my own field: political philosophy. Here’s an uncomfortable question: if the volume of academic research in political philosophy were cut in half tomorrow, would anyone notice? Sadly, I can see a good case for the answer that, apart from a couple of academics, relatively few people would notice.

There’s more, but I’ll stop there. What explains these puzzles? Well, the signaling model of education does pretty well. If colleges are just a signaling device/holding pen for talented youths, then much of this makes sense. Our job is to slap a “good worker” signal on students’ foreheads and collect some socially harmful rents while we’re at it. But I’m still having trouble explaining certain puzzles, like the emphasis on research. And, even if the signaling model is broadly correct, there’s still some role for human capital. How to explain the above puzzles if universities are even weakly motivated to actually promote learning?

The post Puzzles about College appeared first on Bleeding Heart Libertarians.

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nikolap
131 days ago
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nikolap
147 days ago
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