Sunday, 12 June 2011

Evolutionary autism?

My sister blog 'Feed me research' (named in honour of everyone's favourite monster) carries a link to a recent article published in the journal Evolutionary Psychology by Jared Reser. The name of the journal perhaps gives away what the aim of the paper was: conceptualising autism from an evolutionary psychology perspective.

Probably best if I start from the beginning. Evolutionary psychology is a branch of psychology which sees the various human psychological traits and abilities as being the result of adaptations down the ages in much the same way as that of evolutionary biology. The main premise is that, psychologically, we are what we are today as a result of our overcoming various struggles and barriers that have confronted humankind in the past. So setting the wayback machine to several thousand years ago, our ancestors lived close to nature, very close to nature. After perhaps a few thousand or million encounters with spiders and snakes for example (particularly the poisonous variety), by some, as yet unknown process, a fear response is passed down the ages, and hey presto... 'get that spider away from me' or worse, arachnophobia and ophidiophobia. A classic gene-environment partnership at work perhaps?

Bearing this in mind, the paper in question goes into quite some detail describing how the various behaviours associated with 'modern-day' autism might have come about as a result of our ancestral lives, with particular focus on the 'solitary forager' hypothesis [forthwith to be called the SF hypothesis]. The SF hypothesis is based on the fact that before we were able to pop down to the supermarket and buy our tinned baked beans, even before we started cultivating beans as crops, humans were reliant on finding and eating what they could. I use beans as an example here but because the flux capacitor on my DeLorean is not quite in time-travelling mode at the moment, I can't precisely confirm how long haricot beans have been around. You get the gist anyway: we had to search out or 'forage' for our food. The solitary side of things stems from, well.. acting and being on one's own. In this case, searching out those all important food sources without the aid of a social group, which is perhaps advantageous particularly when food is scarce (who want's to share anyway).

Reser quite extensively goes through the various symptoms associated with autism together with other lines of enquiry to develop the SF theory. The obvious correlation made is the proposed social interactive side of autism, where like other species, the suggestion is that early humans were in the most part programmed to live the solitary life for most of their existence and so social skills were put on the backburner until required for those je t'aime Serge Gainsbourg moments. There are various other examples laid out, including how repetitive and inflexible behaviour patterns may have been beneficial for looking for certain types of food in certain areas as well as detecting and responding to threats. The support for the SF hypothesis comes from areas such as the 'extreme male brain' hypothesis and the 'map-reading = good, being a vicar = bad' skills suggested therein.

So what's the verdict on the SF hypothesis?

Well generally speaking, I have some time for the evolutionary perspective... at least to a degree. If you scroll down to the bottom of this blog you will see a link to Emily Dean's Evolutionary Psychiatry blog, which does an excellent job at highlighting how our modern-day living is perhaps a few steps ahead of what we humans were originally programmed for and the potential effects on our physical and mental health. Indeed, my research interest on the use of gluten- and casein-free diets as potential effectors of some cases of autism, inclines me to think that there might be something in concepts such as Paleo and Paleo 2.0; heavily dependent on where we were and where we are today and the disparity between the two. Drinking the secretions from another animal? Eating only recently cultivated grains? Probably not something that our early ancestors were doing in great quantities, although I admit that the evidence is not yet conclusive. Additional note: who first pressed their lips to a cows udder and thought 'mmm, that's not so bad'?

Reser does make quite a good attempt in portraying autistic symptoms in an evolutionary 'positive' light and some bloggers have seen something in the proposed theory. I suppose taking the example of natural selection, if autistic symptoms were not at some point 'beneficial', or in some cases, remaining beneficial, would they have not been naturally-selected out? A post for another day on assortative mating perhaps.

I can see the counter perspective also. We should be cautious in how we apply such a hypothesis to modern-day autism particularly with the potential for the more negative side of such writings relating to evolution and advancement. I understand that Reser did not set out to write this piece with such ideas in mind, but for some people this could be construed as offensive. There is, as far as I am aware, no physical evidence to corroborate 'evolutionary autism' or indeed the fact that all the traits were present, and present all at once, in any or every person of the Paleolithic era. Autism is an extremely heterogeneous condition, which covers a wide, wide, wide spectrum of presentations and abilities (and co-morbidities). Autism or autisms? In cases where daily living skills are not impaired, I could see how superior focus on details a la weak central coherence and repetitive patterns of behaviour would be advantageous if not life-saving when spotting lions in the grass or keeping a mental record of which berries are poisonous and which are safe, tasty and nutritious (no, iPads weren't around in the Paleolithic era unless there was the Flintstones equivalent - the iRock). I do find it a little more difficult to generalise such skills to those cases where autism is so extreme that almost constant care is required to do the most basic of things. Don't also even get me started on questioning what the evolutionary advantage of accompanying iron deficiency or bowel problems or ADHD or learning disability or other co-morbidities might have (not) been.

This is not the first time that 'evolutionary autism' has been suggested and discussed, and no doubt won't be the last. We all come from somewhere and I suppose this paper takes a good a shot as any at where and how. The final questions however have to be: what is the benefit of such hypotheses to people with autism in the modern world? Is it empowering to know that hunter-gatherers might have shown certain autistic traits? Is such information going to significantly improve quality of life for people on the autism spectrum today or tomorrow? Questions that I can't answer.

To finish, have a read of a previous post on drawing lines.