Wednesday, July 13, 2016

Genetic Memory

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.

Genetic memory is invoked to explain the racial memory postulated by Carl Jung. In Jungian psychology, racial memories are posited memories, feelings, and ideas inherited from our ancestors as part of a "collective unconscious".

Language, in the modern view, is considered 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.

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 "The 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.

The idea of past life regression being the result of specific experiences encoded into genes has generally been dismissed by parapsychologist because subjects have no proven genetic or familial links with the person who is the object of the regression. They generally agree with the biological view that genetic traits are dispositional — i.e. that they merely encode a disposition to react in certain ways to environmental stimuli, and not actual memory or experience.

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