After examining only poor families, Eric Turkheimer found that "intelligence was... Near 0 percent" (79) inheritable. This claim showed that "there is no set portion of genetic influence on intelligence" (79). Taking this claim into account and the notion of GxE, why then do some people excel at an early age? Could the same level of genetic influence of intelligence be expected in rich families? Or, as Matt Ridley suggests, do these numbers "pertain only to groups" (79) and when looking at the individual, genetics do put one above others?
Sai Nimmagadda (saiguy@me.com)
It is true that heritability of genes is actually a much lower percent than previously suggested by scientists, but many children are able to excel at an early age mainly due to their environment. One example would be the famous musician Wolfgang Mozart; Mozart did not have a special “talent” gene, but he did arise to become one of the greatest musicians that ever lived. The environment that he was born into trained him to become a great musician since his dad was a great music teacher with a revolutionary way of teaching and the experience of knowing how to teach a child from Wolfgang’s older sister, Nannerl Mozart. Thus Wolfgang got one of the best musical educations possible literally from his infancy. As Shenk notes, “Literally from his infancy, he was the classic younger sibling soaking up his big sister’s singular passion” (62). This is very important to Mozart’s success because by the age of three, ninety percent of the baby’s neurons in the brain are developed, and so Mozart’s brain was formed around the music he was exposed to. Scientists hypothesize that neurons are “plastic” and are able to adapt to different stimuli. This led to a highly developed cerebellum, which processes rhythm and timing, the corpus callosum, which acts as a translator for the brain to the left and right hands (http://www.brillbaby.com/early-learning/introduction-to-early-learning/why-is-early-learning-important.php). Wolfgang not only was exposed to music early on, he was also fascinated with playing music. This was the motivation that was required along with constant practice, which his father demanded. Mozart excelled early on in life mainly due to the constant exposure to music; this exposure trained his brain to absolute pitch and great musical memory. This made him a child prodigy because as Shenk states, “child prodigies are not adult level innovators but masters of technical skill) (62). A recent study showed that musicians with absolute pitch had a more developed left planum temporale than someone without absolute pitch (http://www.brainmusic.org/EducationalActivitiesFolder/Popp_genius2004.pdf).
ReplyDeleteYiran Xu, yxu135@gmail.com
Mozart’s efficient and effective practice style, constant exposure to music during the crucial critical period, and constant practice made Mozart a musical prodigy; however, the skills are very specific to that field (Shenk 65-66). The same level of genetic influence of intelligence can be expected in rich families; there is no clear trend that children of rich families are smarter or more successful than children of poor families. One factor that could result in intelligent children is the environment created by their parents. Rich families are able to create a more stable and enriched environment for their children while a poor family might not. However, the trade-off is that the poor child grew up in an environment that demanded change and gives them the drive and determination to be study and be successful. The rich children might not have the environmental pressure to be successful and be content with their life. Rich families are able to introduce their children to activities to increase intelligence such as early start programs, sports, or playing a musical instrument. The neurons in the brain will adapt to those conditions causing a dynamic change in intelligence (http://scicasts.com/lifesciences/1874-bioresearch-disease-studies/3954-brains-connective-cells-regulate-earning-and-memory). By exposing children to stimuli, their brains retain most of the neural connections during the “pruning” stage, where the brain erases unused neural connections for efficiency; more neural connections means greater processing speed. Another environmental influence is the effect of communication around the child during development as seen in the experiment conducted by Hart and Risley (Shenk 45-46). They tallied up how many words were spoken in homes of different economic classes, and the result was that by age four, children of professional’s homes were exposed to a total of over 32 million words than children in welfare homes (Shenk 45-46). Children born into welfare homes might actually have defective genes since there is a trend of people on welfare that smoke and drink and do drugs. When a mother smokes during pregnancy, the baby is exposed to nicotine, carbon monoxide, and tar (http://www.marchofdimes.com/pregnancy/alcohol_smoking.html). The carbon monoxide would strongly bind to the hemoglobin in the baby’s red blood cells and cause less oxygen to reach the baby’s body and brain, which could cause severe brain damage (http://ehealthmd.com/content/how-do-smoking-and-drinking-affect-pregnancy). If the brain doesn’t have enough oxygen, the neurons and glia which are abundant in the hippocampus and the cortex cannot develop properly and not only will they not adapt to different stimuli, but they will also cause a decrease in intelligence.
ReplyDeleteYiran Xu, yxu135@gmail.com
The reason why intelligence can’t be inherited is because it is mostly based on the environment of a child. When the parents are smart, the kids are not automatically smart due to genetics. The reason why there is a high chance that the children will be smart at early ages would be because of the environment provided to the child by the smart parents. For example, due to smart parents, they may enjoy reading and would provide their children with numerous books to read. This would create a higher intelligence level in the child at a young age. Shenk states that there are certain triggers to stimulate intelligence in a young child: speaking to them early/often, reading early/often, nurture and encouragement, high expectations, embracing failure, and promotion of a growth mindset (47). All of these things have to do with the environment that the child is put in.
ReplyDeleteThe reason why these environments would make them smarter is because their brains would be worked harder at a younger age. This may trigger an early change in gene expression. If the child’s learning environment turned on or off certain genes at an early age to meet the environment’s demands, this would cause a higher intelligence in a child with a better learning environment as opposed to one that isn’t. Shenk states that “every human being can grow smarter if the environment demands it” (44). The turning off and on of genes could occur by DNA methylation of DNA acetylation. This would be the expressing of genes by loosening the histones of the chromatin, or simply disrupting any part of the central dogma theory. One example is of the rich families versus the poor families and speaking skills in Hart and Risleys’ experiment. The rich family child was exposed to around “fifteen hundred more spoken words per hour than” the poorer family’s house. This is a prime example of the large difference different children’s learning environment. The rich child must have been exposed to thousands of more words earlier in life and was forced to understand them due to his or her environment, causing a change in gene expression early in life and could have made the child verbally smarter. Also, if a child is given different problems to solve at an earlier age, it forces his or her brain to work in different ways around the problem using different problem solving methods (http://www.trans4mind.com/counterpoint/index-child-development-parenting/andrews7.shtml).
Triggers such as reading, speaking, problem solving, etc. are able to make a child smarter through change in gene expression. This change could occur by temporary changes or enduring changes in gene expression. When describing the switching on and off of genes, this could be switching on genes that help increase cell growth in the brain and switching off genes that inhibit this growth by disrupting the transcription or translation of the gene to protein process (developingchild.harvard.edu/index.php/download_file/-/.../666/). This also could mean switching on genes to increase protein production in the brain to create more synapses between neurons to create more connections to help memory development in a child’s brain (http://www.scientificamerican.com/article.cfm?id=experts-short-term-memory-to-long-term). This increased memory span can also contribute to the child’s increased intelligence. Lastly, the reason why people could excel at an early age is because that is when the brain is still developing. Harvard scientists claim that the “chemical signatures” imprinted on a developing brain are the ones that can alter gene expression early in life. These chemical imprints help to regulate the gene expression into creating certain proteins to meet the environment demands (developingchild.harvard.edu/index.php/download_file/-/view/). This could also mean that the chemical signatures that appear during early developments of infancy could possible affect the intelligence of a child years later due to the synapses that have already been produced and the larger cells in the brain that have already been made.
ReplyDeleteEven though there may be a rich “group” that could provide a good learning environment for children to have greater intelligence, there isn’t one necessarily. For one reason, even though families are rich, they may not spend their money in the same places. One family could buy books, another toys, and another luxurious diapers. It all depends. However, it is likely that the children will be successful within that rich group. This is because environment they are raised in, the things they are exposed to, and the way they are taught to carry themselves (Gladwell). For example, a child in a poor family may not have the same confidence in speaking to one of a higher authority that a rich family. Also, the amount of opportunity in a rich community is a lot higher than in a poor community. According to Gladwell, intelligence would probably not be able to be grouped, but success in business, sports, etc. could be.