Chromosome 7: Instinct. Many determinist views about human behavior that have all been revoked are listed, such as Freudianism, Marxism and others, and Ridley implies that genetic determinism of human instinct is much more probable. Human grammar is one of the best examples of this – vocabulary is certainly not innate, but grammar might be, because young children can speak with perfect grammar even before learning it. There is a gene on Chromosome 7 that has been linked to a disorder called SLI (Specific Language Impairment), for which the heritability has been shown to approach one hundred percent. Through a study of an English family with history of the disorder, Canadian Myrna Gopnik proposed that SLI does not have its roots in the physical act of speaking, but rather in the ability to learn grammar rules. Individuals with SLI can communicate but must have a much larger vocabulary (past tense verbs would feel like separate, unrelated words) because of the lack of internalized grammar, similar to adults trying to learn a foreign language. It has been found, however, that a mutation to this gene causes a lesion in the brain affecting not only the grammar part, but also the Broca and Wernicke areas which control face movement and hearing respectively. Ridley also ties grammar instincts to natural selection as a means of survival. [tu, o]
Tylko tyle – po półgodzinnym szukaniu, choć być może siedzę oczywiście w niewłaściwym bąbelku – udało mi się znaleźć merytoryki na zapytanie „instinct gene discovered”. Opis jednego dziedzicznego zaburzenia – nie instynktu – którego mechanizm wcale nie musi być taki sam, jak pierwotnego zjawiska, a poza tym dużo kategorycznych naukowych stwierdzeń typu „might”, „rather”, „imply” czy „proposed”. W porównaniu do poznanych mechanizmów dziedziczenia koloru oczu czy włosów – nawet nie zero, tylko minus jeden.
Szach mat, ateiści.