Tag Archives: evolutionary psychology

Theory of Mind and Language Evolution; What can psychopathology tell us?

Theory of Mind is the ability to infer other persons’ mental states and emotions. It is thought to have evolved as part of the human’s social brain and probably emerged as an adaptive response to increasingly complex primate social interaction.

Brüne and Brüne-Cohrs (2006) explore the ‘evolutionary cost’ of language evolution:

This sophisticated ‘metacognitive’ ability comes at an evolutionary cost, reflected in a broad spectrum of psychopathological conditions. Extensive research into autistic spectrum disorders has revealed that theory of mind may be selectively impaired, leaving other cognitive faculties intact. Recent studies have shown that observed deficits in theory of mind task performance are part of a broad range of symptoms in schizophrenia, bipolar affective disorder, some forms of dementia, ‘psychopathy’ and in other psychiatric disorders.

Now it’s fairly uncontroversial to assert that without the ability of theory of mind humans would have never evolved language (Sperber and Wilson, 2002). This is due to the fact that if one can’t attribute another to have a ‘mind’ like ones own, or assume that other minds hold different information to ones own then one would see little point in trying to share information. (I’m sorry for the amount of ‘ones’ in that sentence).

Sooo, it does not seem presumptuous to assume that people interested in the evolution of language should be interested in theory of mind, in fact for many years evolutionary linguists, psychologists and biologists have been looking into this, but mostly through observing the behaviour of animals, and especially primates to see if they display theory of mind capabilities. A good summary of this work can be found here, and a lot of relevant studies can be found on this blog in the What makes humans unique? posts by Michael. I’m not going to look at the animal data in this post, but instead what the deficiencies in some human conditions can tell us about the evolution of theory of mind. That is, what can autism, schizophrenia, bipolar affective disorder, dementia, ‘psychopathy’ and other psychiatric disorders tell us?

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How and Why did Madness Evolve??

I’m reading a book at the minute called ‘The descent of madness: Evolutionary Origins of Psychosis and the Social Brain’ by Jonathan Burns. I thought I’d summarise some of the theories in the book as to how schizophrenia came about, for the principle reason that it’s very bloody interesting.

Some evolutionary thinkers have posited that schizophrenia is a recent disorder which is a modern response to the stresses of the industrial and technological age. Burns argues against this and claims that there is evidence of schizophrenia from early human history.

So, how and why did schizophrenia evolve when it has such a maladaptive nature? It’s certainly not being selected out because the phenotype still persists with a similar rate of incidence across the human race.

The Adaptionist Programme has a solution for this problem of mental disorders in that it views them as behavioural traits which evolved due to an advantage for the the individual in the ‘ancestral environment’, however, now, in a world which has changed and become psychologically stressful, a mismatch is created between the evolved trait and the modern environment.

The persistence of the phenotype can also be explained by taking into account the fact that psychotic illness has a continuum on which schizophrenia is a severe end of the spectrum, because of this other phenotypes on the genetic spectrum could harbour particularly adaptive traits. Genetically related but unaffected individuals who share some of the milder features of the illness may possess some kind of evolutionary advantage and hence the phenotype would linger.

The hypotheses above are plausible by Jonathan Burns claims he has a better solution:

Our hominid ancestors evolved a sophisticated neural network supporting social cognition and adaptive interpersonal behaviour (in other words the social brain). This has been identified, using functional imaging, to be comprised in the fronto-temporal and fronto-parietal cortical networks. Psychosis (and schizophrenia in particular) are characterised by functional and structural deficits in these areas and hence the term ‘social brain disorders’ are fitting.

Schizophrenics display abnormalities in a wide range of social cognition tasks such as emotion recognition, theory of mind and affective responsiveness and as a result individuals with schizophrenia find themselves disadvantaged in the social arena and vulnerable to the stresses of their complex social environments.

So, since there is such evidence to support that the areas which comprise our ‘social brains’ are the same regions which contribute to the disorder of schizophrenia when functional and structural deficits are present it becomes clear that schizophrenia exists as a consequence to the complex social brain.

This is a desirable hypothesis due to the fact that it does not rely on a Cartesian model of an isolated ethereal mind separated from body and environment, and instead concentrates on a physically and socially integrated construct of mind, embodied in the living world.

Interesting.

I’d just like to add a small disclaimer which says that I’m not an expert in schizophrenia or pretty much anything I’m writing about here (I haven’t even finished the book) so sorry if I’ve got anything hideously wrong. Please tell me. I’ll revisit this with extra thoughts on the subject once I have finished the book.

In other news and on the subject of evolutionary psychology here’s a really fun and ridiculously geeky thing I found:

Evolutionary Psychology Bingo!

Reading Round Up

Here’s some stuff I’ve been reading over the last month or so:

Okay, so that brings you up to date with my reading from May through to July. Next round up will cover August. How fascinating :-/


Current Issues in Language Evolution

As part of my assessment this term I’m to write four mock peer-reviewed items for a module called Current Issues in Language Evolution. It’s a great module run by Simon Kirby, examining some of the best food for thought in the field. Alone this is an interesting endeavour, after all we’re right in the middle of a language evolution renaissance, however, even cooler are the lectures, where students get to do their own presentations on a particular paper. I already did my presentation at the start of this term, on Dediu and Ladd’s paper, which went rather well, even if one of my slip ups did not go unnoticed (hint: always label the graphs). So, over the next few weeks, in amongst additional posts covering some of the presentations in class, I’ll hopefully be writing articles on these four five papers:

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