Genetic memory (psychology)
In psychology, genetic memory is a memory present at birth that exists in the absence of sensory experience, and is incorporated into the genome over long spans of time. It is based on the idea that common experiences of a species become incorporated into its genetic code, not by a Lamarckian process that encodes specific memories but by a much vaguer tendency to encode a readiness to respond in certain ways to certain stimuli.
Language, in the modern view, is considered[by whom?] to be only a partial product of genetic memory. The fact that humans can have languages is a property of the nervous system that is present at birth, and thus phylogenetic in character. However, perception of the particular set of phonemes specific to a native language only develops during ontogeny. There is no genetic predisposition towards the phonemic makeup of any single language. Children in a particular country are not genetically predisposed to speak the languages of that country, adding further weight to the assertion that genetic memory is not Lamarckian.
Trauma, phobias, and neuropsychiatric disorders
Neuroscientific research on mice suggests that some experiences can influence subsequent generations. In a study, mice trained to fear a specific smell passed on their trained aversion to their descendants, which were then extremely sensitive and fearful of the same smell, even though they had never encountered it, nor been trained to fear it.
Changes in brain structure were also found. The researchers concluded that "[t]he experiences of a parent, even before conceiving, markedly influence both structure and function in the nervous system of subsequent generations".
Scientists speculate that similar genetic mechanisms could be linked with phobias, anxiety, and post-traumatic stress disorders, as well as other neuropsychiatric disorders, in humans.
In contrast to the modern view, in the 19th century, biologists considered genetic memory to be a fusion of memory and heredity, and held it to be a Lamarckian mechanism. Ribot in 1881, for example, held that psychological and genetic memory were based upon a common mechanism, and that the former only differed from the latter in that it interacted with consciousness. Hering and Semon developed general theories of memory, the latter inventing the idea of the engram and concomitant processes of engraphy and ecphory. Semon divided memory into genetic memory and central nervous memory.
This 19th-century view is not wholly dead, albeit that it stands in stark contrast to the ideas of neo-Darwinism. In modern psychology, genetic memory is generally considered a false idea. However, biologists such as Stuart A. Newman and Gerd B. Müller have contributed to the idea in the 21st century.
- In the Assassin's Creed universe, genetic memory is decoded by a virtual machine called the Animus. The Animus decodes and renders memories in a three-dimensional field, allowing the reliving of previous events and the discovery of hidden information.
- In Jean M. Auel's The Clan of the Cave Bear, the Neanderthals are able to tap into their shared genetic memory via hallucinogenic herbal concoctions created by their medicine men and women, and sometimes even without using the drug. It is explained in the novel that while this allows them access to a vast array of survival skills learned over thousands of years of slow evolution, they lack the ingenuity and innovation to advance beyond what they already know, and are thus doomed to die out as a species. The Cro-Magnon, who in the novel do not have access to their genetic memories, instead possess a more developed frontal lobe and are thus able to reason and deduct at a level far beyond the Neanderthal.
- Rodolfo R. Llinas (2001). I of the Vortex: From Neurons to Self. MIT Press. pp. 190–191. ISBN 0-262-62163-0.
- Dias, Brian G; Ressler, Kerry J (2013). "Parental olfactory experience influences behavior and neural structure in subsequent generations". Nature Neuroscience. 17 (1): 89–96. PMC . PMID 24292232. doi:10.1038/nn.3594. Lay summary – New Scientist (December 1, 2013).
- Callaway, Ewen (2013). "Fearful memories haunt mouse descendants". Nature. doi:10.1038/nature.2013.14272.
- Gallagher, James. "'Memories' pass between generations". BBC. Retrieved 1 December 2013.
- Louis D. Matzel (2002). "Learning Mutants". In Harold E. Pashler. Steven's Handbook of Experimental Psychology. John Wiley and Sons. p. 201. ISBN 0-471-65016-1.
- Timothy L. Strickler (1978). Functional Osteology and Myology of the Shoulder in the Chiroptera. Karger Publishers. p. 325. ISBN 3-8055-2645-8.
- Brian Keith Hall; Roy Douglas Pearson; Gerd B. Müller (2003). Environment, Development, and Evolution: Toward a Synthesis. MIT Press. p. 17. ISBN 0-262-08319-1.
- The Science Fact Animating Assassin's Creed's Animus. Kotaku.com. April 11, 2012. Retrieved November 8, 2015.
- Alan Bullock; Oliver Stallybrass (1977). "Genetic memory". The Harper Dictionary of Modern Thought. Harper & Row. p. 258.
- Raymond Joseph Corsini (1999). "Genetic memory". The Dictionary of Psychology. Psychology Press. p. 410. ISBN 158391028X. —Note that the definition talks of "information based upon" learning and experience, rather than about learning and experience themselves.Z