Currently, research studies have agreed that both genetic factors and environmental factors will influence intelligence. On intellect, there is a reaction spectrum, which means that degrees position on the impact on intelligence of genetic factors. Inheritance sets an upper and lower limit on the IQ that a single individual can achieve. The atmosphere can decide, in certain cases, the degree of intelligence that the child gains as it grows. Intellect appears to run in the family and intelligent children learn their abilities from their parents as evidence of genetic influence. Research on twin studies displays a higher connection among identical twins in intelligence than among fraternal twins. It also appears in research conducted among identical twins separated after an extended period living in different environments. Adopted studies indicate that adopted child displays resemble in intelligence with their parents.
Evidence of the environmental influence indicates that adopted children tend to show similar intelligence level to those of their adopted parents. Adopted studies also show that children reared together have simple levels of intellect. The findings are correct even when identical twins nurtured together are matched to identical twins nurtured apart. Moreover, naturally distinct children mentored together in the one home have some similar levels of intelligence. There is a decrease in intelligence among children who live in deprived homes. However, their intellect increases when they move to wealthy families. Levels of aptitude tend to be higher in developed countries compared to developing countries.
How is intelligence determined by environment and genetics?
Intelligence is the ability to solve problems and adapt to new environmental experiences. The structure of aptitude is best divided into two the environment and the genetic factors. It is usually tough to define the concept though intellect can be defined as the capability of the brain to think logically and acquire new knowledge (Burton, Westen, and Kowalski, 2002). Psychologists have not agreed on a precise definition of intelligence. Moreover, intellect can be divided into reasoning, problem solving, and memory, therefore, creating a consistency for measuring of intelligence becomes a problem. An individual with aptitude in the family tend to be intelligent himself or herself, and this brings to question whether one inherits intelligence or learns from the environment.
Hackman, Farah, and Meaney (2010) conducted a review to determine the role of genes and environment, which is nature and nurture in ascertaining the intelligence of a child. Findings obtained in this studies indicated that the heritability of intelligence was between 0.4 and 0.8 in the United States, which explained the most of the children had a variation in intelligence because of their genetic factors. Other factors from the environment also indicate a significant influence on intellect among this children.
The environmental difference can be determined by deficiency representation of social class, and intelligence comprises of three variables. The variables include development and performance, which correlated with the social status of the individual. The variables consist of the arrangement of birth sequence, diet, and prenatal concern. For example, first-born score better in mental tests compared to other children. Parental stress and undernourishment are found among children from lower economic status. Scientists have proved this by conducting tests on two brothers living in different contexts, and the one who was exposed to supportive environment indicated an increased level of intelligence than the one that was open to the poor environment.
A fetus may lack enough food, blood supply that in turn affects its development leading to low intelligence in the child when it is delivered. The conditions the fetus is exposed are both genetic and result from environmental circumstances and are recognized to as legitimate factors, which affect the intelligence of a child. Cultural variable influence the intellectual difference between children, and it appears that children from economic status have different behavioral patterns from those who come from the wealthy financial situation. Additionally, researchers have proved that the interaction a mother has with a child while still young can quickly affect the intelligence of the child. The young ones who are protected wormed and well fed usually develop neurons that promote an increase in the level of aptitude. The findings indicate that maternal bonding with the child while still young helps in the development of the Childs intellectual abilities. Similarly, early neglect of children, when they are young, makes develop weaker skills to pick up environmental factors that will foster the development of intelligence in their environments (Burton, Westen, and Kowalski, 2002).
Research studies have indicated that intelligence is a byproduct of an individual’s inheritance and environmental factors. Findings on intellect and the environment help in understanding the human group difference in intelligence and other measures of cognitive ability. In children, genetic factors contribute twenty to forty percent influence on intelligence and eighty percent in adulthood. Therefore, the environment and its variation contribute to variation in intelligence between individuals. The environment is in a position of modifying genetically determined factors that determine the aptitude of an individual. However, the function performed by heredity and environment remains differences. The genes that help an individual gain instances using the different environmental factors determine the increase of inheritability intelligence with age. People with high intellectual pick environmental factors and end up having high intelligence. In children, the child is still developing. Thus, there is the chance of environmental stimulus to affect its development, and they get to adulthood there is no change in the environmental influence because the brain has already developed (Burton, Westen, and Kowalski, 2002).
Heritability of intelligence reaches at its pick at the age of eighteen and twenty. The shared environmental influence also decreases with age as the individual enters adulthood. During brain gaining, several environmental factors can damage the brain by producing unique neuronal damage. The defense and repair procedures are genetically determined, and the presence of functional variants within genetic factor elaborates in neuronal safety (Burton, Westen, and Kowalski, 2002).
Researchers have studied twins who were separated at birth to determine the effect of nature on their intelligence. They claim that if the mentality is purely biological, identical twins should have the same intelligence levels when they became older in different contexts. In most cases, this is not usually the case because gifted children pick out stimulating factors that further increase their intelligence. In most cases, programs used to stimulate intellect will always increase the levels of intelligence among children because their minds get cognitive stimulating thoughts from the environment. Findings also indicate that children offered training might also enhance their levels of aptitude through different training programs. Additionally, research has proved to affect the intelligence of a child because children exposed to extreme poverty lack enough motivation in their environments that can trigger the development of intellect (Burton, Westen, and Kowalski, 2002).
Improvements on nutritional values have also proved to be important in the increase in intelligence among the children. Prenatal and early diets are connected to brain construction, conduct, and intellect. Studies have proved that providing some foods to children can help in the intellectual development as the brain develops. Lack of Zinc, Iron, folate, iodine, B12, and protein can contribute to poor intellectual development in children (Stuppia Cieri, Antonucci, and Gatta, 2010). Another study conducted by revealed that there was no relationship between breastfeeding mothers and the bits of intelligence of their babies. However, Beaver (2014), discovered that breastfeeding of children contributed to the development of their intellectual capacity.
Supplementation with creating contributed to increasing in intelligence the elderly rather than young adults. Other studies have proved that creatinine can boost cognitive performance in young adults. However, long-term provision of the supplement can contribute to adverse negative effects. In another study conducted by Schulenburg, music skills can be transferred to the increase of intelligence among children. Moreover, people improved their performance through listening that motivated their mood to listen and learn new materials presented. In adults, there is a positive correlation between adult training and their intelligence (Stuppia Cieri, Antonucci, and Gatta, 2010).
Genetics of intelligence studies how many genetic factors affect the aptitude of an individual. Since both genes and environmental factors can determine intellect, it becomes difficult to define intelligence without incorporating the two factors because the ability of a person cannot happen without the effect of genetic factors. However, with the genetic factors, so many environmental factors affect the intelligence of an individual. Starting from conception, the health of the mother can influence the development of intelligence of a newborn child. As mentioned earlier the exposure to toxic substances can diminish the developmental of intellectual abilities in the child. Humans are impressively high and can improve from an incredible amount of undesirable environmental influences. Therefore, studies conclude that genetics provides the maximum amount of the exceptional ability an individual can reach, and environment helps that individual realize it, or diminishes that one’s capability to get their innate intellectual ability. Children can also increase their mental abilities through education, which is attained through refining physical strengths, practice or study, and experience of new philosophies, material, and cultures.
Hackman, Farah, Meaney (2010) noted in their study that traits such as hair, eye, and skin color are determined by the genetic factor of an individual. Similarly, intelligence is also determined by genetic factors. According to the nature theory, traits like intelligence, character, violence, and sexual alignment are also in the genetic of an individual. These researchers discovered that genetic effect is excellent in determining the intelligence of an individual (Burton, Weston, Kowalski, 2012). Although these findings cannot be the same among children developing in low economic situations, children that receive proper childcare display high levels of intelligence.
Research on adoption has also been conducted to explain the role of genetics and the environment in intellect. Adoption is a case in point of nature because it explains the difference between children brought up in the same family with the same genetic backgrounds. Another example of nature is a study conducted on monozygotic twins had similar intelligence even after separation than dizygotic twins living together. If heredity did not present a role in influencing intellect, then the dizygotic would have same intelligence level (Beaver, 2014).
The nurture theory believes that the intelligence of a child is caused by a person’s immediate environment, and this implies that environmental factors might include education, socioeconomic status, nutrition, parents’ behavior, alcohol, criminal behavior, emotional alteration, to the extent of time completed interpretation or even viewing television among others. Findings of this study indicate that social and environmental circumstances contribute to the changes in intelligence. Another example is children who experienced a broad diversity of new technical creations motivating them, assisting with pictorial enigmas like those used in intelligence tests (Beaver, 2014).
Plomin, DeFries, Knopik, and Neiderhiser (2013) conducted a genetic research and discovered that individual differences in performance are ascribed to genetic and environmental components of variance. Findings in this study indicated the genetic influence on cognitive learning among the children. Based on the conclusions achieved in this research there are hereditary factors that contribute to intellectual development in children. Similarly, some environmental factors modify the intellectual development among children. Apart from this, other researchers noted that human intelligence is categorized by an extreme level of genetic influence. An enormous percentage of the human genetic factors are supposed to have a result of the expansion and functionality of the mind. Moreover attaining good grades depends on to do many factors like interests in learning, and the willingness to study (Beaver, 2014).
Modern research on biology has always insisted that people are a product of their parents and intelligence mainly depends on genetic factors. Hereditary factors count more that social factors in intellectual developments. An individual can change his skin, but the behaviors and ways of thinking remain genetic. Galton believed that gifted children tend to be intelligent because their fathers must have had high levels of intelligence. Karl Pearson also concluded in their study that the environment had less impact on the intellectual development of an individual (Asbury, Wachs, and Plomin, 2005).
Some factors must be considered when discussing the genetic influence on intelligence. First, heritability gauges the level of difference in a feature that can be accredited to genes of an individual and not the proportion of genetic factors found in an individual. For instance, if the context variation experienced by different people increases then the hereditary figure would decline. In contrast, if everybody had the identical situation, then genetic factors would be hundred percent. The inhabitants in developing countries frequently have more distinct surroundings than in the advanced states. Thirdly, an increased heritability of a trait does not mean environmental factors such as learning contexts influence the intelligence of an individual. In an environment where there is plenty of vocabularies, the people and children in these circumstances will learn a lot of vocabularies compared to those that are exposed to limited vocabulary. Finally, since genetic factors actively influence children during their development stages, it is important to avoid concluding studies based on the effects of environmental factors. Additionally, difference concerns the impacts of the g-factor and the non-g influences with the g factor perhaps being tougher to control and environmental interferences excessively affecting the non-g influences (Beaver, 2014).
Griffiths (2000) discovered in their study that adopted between the ages of four and six in French community displayed reduced levels of intelligence because they come from abusive families, and most of them come from neglected families because they were neglected as infants. After adoption nine years letter they all displayed an increased level of intelligence. Therefore, some bits of intellect were associated with the economic status of the adopted families. Adoption families also tend to be more similar to their economic levels compared to the general population, which underestimates the findings of previous studies. Similarly, Johnson (2010) believed that the quantities of intelligence variance associated with genetic factor and situation vary depending on their socioeconomic condition. The researchers noted that in a study conducted on seven-year-old twins, in deprive families, sixty percent of the inconsistency in early childhood intelligence appeared in the shared family situation. The influence of genetic factor is almost zero in wealthy households, and lastly, the findings are precisely the reverse of the previous studies (Beaver, 2014).
In conclusion, there is no exact definition of intelligence although many researchers define it as the individual cognitive ability. Nature or nurture influence on intelligence remains a topic of discussion between geneticists and environmentalists. Intellect appears to be controlled by both factors. Several factors can contribute to cognitive impairment particularly if they affect a child before birth and immediately after birth. Some of these factors include drug abuse, poor nutrition, and low economic status. Head injuries and mental illnesses that occur in children can also cause cognitive impairment. For example, people living together of the same race had more characteristics of inheritance and tended to be intelligent based on their genetic factors. Other researchers have proved that groups of people with the higher social or intellectual rating have produced children with increased levels of intelligence. For example, royal families tend to children with high intelligent abilities. Therefore, if the environment responsible for a given trait changes the entire population, then the mean value of the genetic factor will not affect the given behavior. Therefore, research has proved that variation in intelligence in a given population could not be because of genetic factors. Secondly, standard error noted in these studies indicated that the value of genetic factor could change because of the impact from the environmental factors.
Researchers believe that the heritability of intelligence is relatively high and these findings prove the tests on intellect. The Monozygotic (MZ) twins resemble one another even when separated for a long time. Results also indicate that full siblings resemble one another closely than half siblings. Genetically related individuals continue to resemble one another eve when living apart. Other findings that show environmental factors influence intelligence whereby people living together tend to have the same level of mind. Adopted children display variation in their level of aptitude. Therefore, both genetic and environmental sources contribute to intelligence variation in children.
Finally, the intelligence of an individual is multifactorial and is influenced by a mass of influences. Nature and nature work collectively in responsible in developing aptitude. Although genetic factors play a significant role in intellectual development, environmental factors also affect intelligence. All these factors can either reinforces or weaken the intelligence of a child.
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