A new edition of synapse, featuring from-the-tracks coverage of the SfN conference, is now available at the Pure Pedantry. Don't miss all the action that is taking place at the SfN.
Sphere: Related ContentA recent study, has determined that a Single Nucleotide Polymorphism (SNP) in the BDNF (Brain deriver neurotopic factor) gene in humans, that substitutes a Met allele for Val, may be a predictor for increased susceptibility to anxiety/ depression. The study involved experiments with mouse homozygous for the Met allele and placing them in stressful situations. These mice exhibited considerable increase in anxiety over normal mouse when facing similar situations. Thus, a potential locus and mechanism for anxiety/ depression has become available.
It is interesting to note that a similar SNP that involves Met/Val substitution in the COMT gene has been implicated in schizophrenia and affects cognitive performance in frontal regions. In the COMT case though, those who have the Met allele are more fortunate, in the sense that the Val allele causes increased metabolism of dopamine and other catecholamines.
While a Met allele is good in a Schizophrenia gene, it has the reverse effect in a depression/anxiety gene! What exactly does the Met / Val difference mean for a gene?
Hat Tip: The Mind Blog
An interesting discussion is going on at slashdot regarding the recent speculation of LSE theorist Oliver Curry, that Humans may split into two species, very much like the Elois and Morlocks conceived by H G Wells, as a result of mate selection.
As per the standard evolutionary theory of how new species are formed, it is posited that new species result form existing species, when interbreeding between two factions of the old species stops and genetic variations accumulate in isolation in the two species making them different from each other and making them further unavailable for interbreeding. The original lack of interbreeding resulting in a species split may be due to accidental genetic changes that make interbreeding troublesome or less likely (or make resultant children unhealthy and unlivable) or it may be a direct result of sexual selection and preferential mating. This theory of a new specie origination has also been experimentally verified in fruit flies.
Oliver theorizes, that sexual selection would become prominent in the near future and eventually lead to the bifurcation of the human species, and this bifurcation would be on intelligence/attractiveness lines, with more intelligent and beautiful (Elois) making one strata and the dim-witted and ugly (Morlocks) making the other strata.
This is not inconceivable as intelligence and attractiveness (things like height, beauty etc) have been found to covary in humans and people do take these factors into account while choosing mates.
An added twist to this provide by the fact that SES or wealth is related to intelligence and thus, the bifurcation would also happen along economic lines. Again, wealth and status are attributes that are heavily involved in mate selection.
But for this process to take shape, inter breedings have to be prevented, or become less and less probable and we know that we, as humans, are still not choosy and do interbreed frequently.
What could accelerate and freeze the process of genetic differentiation between the species is the modern genetic research that may once more lead to eugenics-style human-enhancement efforts, with rich having more of these tools at their disposal vis-a-vis the poor. This is exactly the point that Peter Singer makes in his editorial "Gene Therapy" in today's TOI and comes to a similar conclusion that we may be doomed to a split down the line.
I had speculated on something similar some time back: but my reasoning was more guided by evolutionary pressures that our ancestors might have faced during the EEA and whether that had laid the foundation for the split of human lineage. To be precise, I had speculated that the different foraging styles that our ancestors adopted during the EEA had lead to the evolution of different personality traits consistent with that personality ( there was some research that indicated that a foraging style based on begging or nagging the compatriots incessantly to give food might have had low Agreeableness associated and resulted in the emergence of an Agreeableness trait). Further, once people started assuming a certain foraging and personality style, they might have interbred within that class leading to the emergence of that trait in that population.
Fortunately, once the EEA pressures were over the populations mixed with each other and thus the personality traits dispersed in the population. There is not much evidence to back this theory, but it highlights one important point: there has to be environmental pressure on the species that makes them breed selectively and leads to emergence of new traits. If humanity manages not to screw itself ( by nuclear catastrophe or whatever) , then I cannot see any environmental pressures that would enforce the lack of interbreeding. We can thus sleep assured that we are not going to split in two. There will always be that quirky beautiful lady that marries the dumb ugly squat- motivated solely by that elusive thing called love- and not giving a damn about confirming to the standard sexual selection model- as long as we can ensure that we do not subject her to the evolutionary pressures faced by her ancestors and which have become mostly useless since the time we humans have started controlling our environments.
Update : An interesting sum-up of all the prominent blog postings debunking this claim has been compiled by Coturnix at A Blog Round the Clock. It is interesting to note that while John Wilkins, disagrees with the analysis because he thinks that human speciation, if it happens, will happen due to isolation (Allopatric speciation) and lack of interbreeding and that sympatric speciation is not relevant to us; John Hawks takes a completely different take and assumes that if human divergance can take place, it would be most likely sympatric and requiring natural selection against intermediate phenotypes. He rules out the possibility of all Morlocks shipped to an island and being isolated as a likely scenario! He does mention some intricacies involved in assortative mating and sympatric speciation which are worth musing over. The take home is that we are not going to split!!
My own take, had more focussed on Parapatric speciation, in which environmental pressures are a key factor. Key and drastic environmental changes clubbed with partial isolation (occupation of niches by daughter species) and the resultant selective interbreeding is posited as the mechanism here, and does not require either complete geographic isolation of the two diverging species (required in allopatry) or the requirement that the those heterozygous at the differentiating gene locus have less reproductive fitness compared to those who are homozygous (the sympatry requirement) .
BPS research digest has reported on an interesting study that has found that lifetime reading of fiction leads to enhanced empathetic abilities, while reading non-fiction predominantly leads to the converse effects. although, the study suffers from some limitations ( the usual correlation is not causation and empathetic people might be more drawn to fiction rather than it being the other way round) as well as methodological constraints ( it used familiarity of fiction and non-fiction writers' name as a criterion for exposure to that genre: by this measure I would do well in both cases, as I was a very prolific fiction reader earlier, but in the recent years have been reading non-fiction almost exclusively...so my familiarity with fiction authors doesn't reflect my current fiction exposure), but still the results are tantalizing and the implications profound.
For me that raises the question of whether I should also occasionally post some of my short stories on this blog, in a bid to balance the drop in empathy that my readers will undergo by reading my non-fiction!!
There is another interesting study highlighted in this week's BPS digest, that reveals that a thicker corpus-callosum is required for a right-brain hemisphericality (is it that a thicker corpus callosum ensures that the right mechanism is in place (more communication between the hemispheres) to ensure that the more feminine, talkative :-) , holistic right brain is able to become dominant ? Or is it the other way round, that right brain dominance causes more interconnections between the hemispheres and leads to a thicker callosum?)
There is an interesting post at the Babel's Dawn, highlighting the work of David Rose in relation to SFL.
As per David, some pre-requisites are required for the evolution and development of languages as we know them.
Four conditions are suggested for developing explanatory models that may account for these linguistic phenomena. These include (a) a mechanism for reproducing complex cultural behaviors intergenerationally over extended time, (b) a sequence by which articulated wordings could evolve from nonlinguistic primate communication, (c) extension of the functions of wording from enacting interpersonal interactions to representing speakers’ experience, and (d) the emergence of complex patterns of discourse for delicately negotiating social relations, and for construing experience in genres such as narrative. These conditions are explored, and some possible steps in language evolution are suggested, that may be correlated with both linguistic research and archaeological models of cultural phases in human evolution.
Rose’s four steps required for the growth and survival of language are:
Affective Teaching keeps posting some interesting basic cognitive tutorials and their latest one deals with the different concepts people have regarding intelligence and how that affects performance and attitudes.
As per that tutorial, people can either have fixed (entity) or trait-like view of intelligence/ abilities or a changeable (incremental) or skill-like view of intelligence/ abilities. Interestingly, those with fixed view are more prone to learned helplessness, external locus of control, less persistence and lack of use of learning strategies. On the other hand those with changeable view of intelligence are more persistent, having a mastery goal or orientation and apt to use learning strategies and credit success to effort and strategy.
This same difference in attitudes and outcomes was predicted by my recent blog post where I analyzed the differential effects of providing generic (person based) versus specific (outcome based) feedback and praise. It was surmised that this would lead to differential view of intelligence/abilities as being trait-like or skill-like in nature. It is heartening to note that existing research supports such a differentiation in the conceptualization of intelligence by individuals and also predicts accurately the different outcomes based on different underlying conceptualizations.
It should thus be clear that providing the right sort of feedback to the child is very important so that they hook on to the right conceptualization of intelligence early on. This may also go long way in settling the expertise debate: genius have a mastery orientation and an incremental view of intelligence which is different form the normal trait-like view held by most people. Thus, it is not just the case that that they are either more talented or just better learners (although they are both) ; they also have a different attitude- and a different underlying concept of intelligence/ability- which is very much a result of the environmental feedback they received in childhood ans is instrumental in making them what they are.
As per this post from the BPS research digest, Kanazawa of LSE has made a controversial claim that economic inequality is not the cause of low life expectancy, but that both low life expectancy and economic inequality are a result of the low IQ of the poor people. The self-righteous reasoning is that people with low IQ are not able to adapt successfully to the stresses presented by modern civilization and hence perish. He thinks he has data on his side when he claims that IQ is eight times more strongly related to life expectancy, than is socioeconomic status. What he forgets to mention(or deliberately ignores) is growing evidence that IQ is very much determinant on the socioeconomic environment of its full flowering and a low IQ is because of two components- a low genetic IQ of parent plus a stunted growth of IQ/intelligence due to impoverished environment available because of the low socio-economic status of the parents.
A series of studies that I have discussed earlier, clearly indicate that in the absence of good socioeconomic conditions, IQ can be stunted by as large as 20 IQ points. Also discussed there, is the fact that the modern civilization as a whole has been successful in archiving the sate of socioeconomic prosperity that is sufficient for the full flowering of inherent genetic IQ of a child and as such the increments in IQ as we progress in years and achieve more and more prosperity (the Flynn effect) has started to become less prominent. This fact also explains the Kanazawa finding that in 'uncivilized' sub-Saharan countries the IQ is not related to life expectancy, but socio-economic status is. although, he puts his own spin on this data, a more parsimonious ( and accurate) reason for this is that in the sub-Saharan countries, even the well -of don't have the proper socio-economic conditions necessary for the full flowering of IQ and thus the IQ of both the well-off and poor parents in these countries is stunted equally. Thus, the well-off (which are not really that well-off in comparison to their counterparts in the western countries) are not able to be in any more advantageous position (with respect to IQ) than the poor in these countries. The resultant life expectancy effect is thus limited to that directly due to economic inequality and the IQ mediated effect of economic inequality is not visible.
What Kanazawa deduces from the same data and how he chooses to present these findings just goes on to show the self-righteous WASP attitude that many of the economists assume. After reading Freakonomics, and discovering how the authors twist facts and present statistics in a biased manner to push their idiosyncratic theories and agendas, it hardly seems surprising that another economist has resorted to similar dishonest tactics - shocking people by supposedly providing hard data to prove how conventional wisdom is wrong. Surprisingly, his own highlighting of sub-Saharan counties data that shows that life-expectancy is highly dependent on socio-economic conditions in these countries is highly suggestive of the fact that in cultures where the effects og economic inequality are not mediated via the IQ effects, economic inequality is the strongest predictor of low life expectancy.
Instead of just blaming the people for their genes/ stupidity, it would be better to address the reasons that lead to low IQs and when they are tackled, directly address the social inequality problem , as in the author's own findings, when IQ is not to blame for the low life expectancy, the blame falls squarely on economic inequality (as in the sub-Saharan countries data) .
The 64th issue of Tangled Bank is now up at The Neurophilosopher.
This is the first time that I submitted to the carnival, and would like to take this opportunity to welcome the regular readers of Tangled Bank to this blog. Do take the readership poll on the sidebar and let me know in the comments as to what sort of content you would like to see more often.
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