Samstag, 17. Januar 2015

Evolution of Vulnerability

A new book by David C. Geary will be published in August.

In November 2014 I posted the link of a video where he talks about the main content of his new book.

One of the key points of his talk:

"Traits elaborated through sexual or social selection are especially vulnerable to disruption by exposure to environmental stressors."

"Anything that has been kind of elaborated above and beyond what you would expect just from natural selection is a target for disruption." 

"These traits can be physical, behavioral, or involve brain and cognition."

So, e.g. "typical male strengths" (at least those that evolved trough sexual selection) are especially vulnerable to disruption by exposure to environmental stressors. And if I understand Geary correctly, the same could also be true for 'gender-neutral' traits that were socially selected (e.g. for several traits that are especially elaborated in a particular human population / in certain populations).

[Is the spatial ability of East Asians more vulnerable to disruption by severe environmental stressors than their verbal ability? Is the verbal ability of Aschkenazims more vulnerable to disruption by environmental stressors than their spatial ability? Has anybody ever compared the cognitive development trajectories of Europeans, Aschkenazims and East Asians that suffer from Alzheimer's disease?]


  1. I read one time that higher iq is less heritable than lower iq. It is true??

    Lower intelligence would dominant than higher intelligence like O blood type is ''dominant'' to A blood type.

    Also i read that ''schizophrenia'' genes are related with improve of mental energy where in excess will produce full-blown quasi-mental disease.

    Ashkenazim seems have very lower Alzheimer disease. At least, lol...

    Higher verbal iq of ashkenazim can delay more to develop with a larger period of higher environmental sensibility, same case to spatial iq of east asians. Speculations and speculations...

  2. I am not convinced that a 'higher IQ' has a (much) lower heritability than a 'lower IQ', but it seems obvious that a single bad mutation can cause a low IQ, also if an affected person would have an above average IQ, if that mutation would not be present in its genome.

    1. I understand that as ''complex intelligence'' require complex (it implie, more) genes then higher intelligence combinations are less probably to be completed during limited randomness of conception processe, in other words, when daddy and mom mix their genes and produce a new poor human soul. Other possibility is that lower intelligence, technical intelligence (iq) would be dominant because is demographically prevalent exactly as O blood type. O blood type is not necessarily dominant than others blood types but is predominantly. A, AB and B are new mutations, like higher or complex intelligence.

    2. I don't fully understand your thoughts.

    3. The 0 blood type occurs with the highest frequency, but it's not a dominant allele.

    4. Was a analogy, but you understand. Demographically prevalent but not a genetically dominant phenotype. Like higher intelligence, a "new" mutation ( as A and B Blood type), demographically minoritary. Today lower intelligence are older intelligence 'genes'.

    5. Ok. Now I understand your point. :)