Factors Influencing Intelligence Quotient
Even with the same environmental factors, individual intelligence would vary. Education has a complicated relationship with intelligence; it is both a. I.Q. - Genetics or Environment Fabian Grasso July 1, Debates over Various tests have shown that there is a socio-economic link to IQ as people who are. Studies on the influence of gene–environment interaction on intelligence have shown . Association of intelligence quotient with environmental factors (n= ).
Please note a Intelligence a polygenic trait is a highly complex phenotype which is the net result of a wide range of biological processes and the effect of individual polymorphisms on intelligence is thought to be very low. Human IQ is characterized by a high level of heritability A very large proportion of the over 17, human genes are thought to have an effect on the development and functionality of the brain. While a number of individual genes have been reported to be associated with IQ, none have a strong effect .
There is growing interest in the potential for epigenetics a stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence to influence cognition .
The role of epigenetics in human complex traits such as intelligence is difficult to study for a number of reasons. Epigenetic status can be influenced by factors such as diet and alcohol therefore, depending on the epigenetic mark of interest. DNA methylation is probably the most commonly studied epigenetic phenomenon.
Polymorphisms were measured in the four DNA methyltransferase: The relationship between DNMT3L and adult intelligence was only approaching statistical significance after Bonferroni adjustment therefore the primary finding here is in relation to childhood intelligence. The potential involvement of epigenetics and imprinting in particular, raises the intriguing possibility that even the heritable component of intelligence could be modifiable by factors such as diet during early development . However, it is likely that the potential of epigenetics to explain the heritability of intelligence is small.
Effect of environmental factors on intelligence quotient of children
Recent studies have shown that most of this heritability can be explained by a combination of thousands common polymorphisms in DNA sequence across the genome .
Rare DNA variants have not been extensively studied yet on a genome-wide scale. The Flynn effect in defined as the sustained increase in the raw intelligence of human over time. IQ test scores have been rising at an average rate of around three IQ points per decade. Attempted explanations have included improved nutrition, a trend toward smaller families, better education, greater environmental complexity, and heterosis the occurrence of genetically superior offspring from mixing the genes of its parents.
Another proposition is the gradual spread of test-taking skills. This heritability value suggests that about half of intelligence is more or less determined or caused by a child's genetics and biology. The other half is determined by environmental factors which include children's socioeconomic status a measure of family wealth and social statusparent and caregiver attitudes towards education whether they believe it is importantcultural and educational opportunities, and other similar social factors.
Cultural Influences on Intelligence IQ scores are influenced by specific cultural experiences, such as exposure to certain language customs and knowledge from an early age.
Environment and intelligence - Wikipedia
For instance, many low-income African American children are raised with a language style which may be characterized by an emphasis on story telling and the recounting of personal experiences e. Smith did this morning? Many questions appear in this conversational style, but a fair portion of the time, they function more as rhetorical devices designed to engage a conversation rather than as specific requests for precise information. This style of questioning encourages social bonding but it is not particularly good preparation for traditional intelligence tests which typically demand that children generate a specific single correct response to an examiner's questions.
Being used to thinking and responding differently in their day to day lives versus what is demanded of them during testing, such children can end up scoring lower on IQ tests than equally-intelligent peers simply because the testing situation itself does not well fit their life preparation.
In contrast, caregivers in middle income and above white and Asian families tend to spend a fair amount of time asking children specific knowledge-based questions that have a single "correct" answer e. What shape is a stop sign? These knowledge-based questions are more like the questions that are used in traditional IQ tests. The effect was equivalent to an increase in IQ of around 6 points.
Environmental enrichment neural Environmental enrichment affects cognition and intellectual development from a neurobiological perspective. More stimulating environments can increase the number of synapses in the brain which increases synaptic activity. In humans this is most likely to occur during the development of the brain but can also occur in adults. Most of the research on environmental enrichment has been carried out on non human animals.
First, rats were isolated, each to its own cage.
In a second condition, the rats were still in isolation, but this time they had some toy, or enriching object in the cage with them. The third condition placed the rats in cages with each other, so they were receiving social enrichment, without any enriching object. The fourth and final condition exposed the rats to both social interaction and some form of object enrichment. However, studies where environmental deprivation has occurred provide insight and indicate that a lack of stimulation can lead to cognitive impairment.
Further research using educational attainment as an indicator of cognitive stimulation have found that those with higher levels of education show fewer signs of cognitive aging and that stimulating environments could be used in the treatment of cognitive aging dysfunctions such as dementia.
Nutrition[ edit ] Nutrition has been shown to affect intelligence prenatally and postnatally. The idea that prenatal nutrition may affect intelligence comes from Barker's hypothesis of fetal programming, which states that during critical stages of development the intrauterine environment affects or 'programmes' how the child will develop.
Barker cited nutrition as being one of the most important intrauterine influences affecting development and that under-nutrition could permanently change the physiology and development of the child. Birth weight needs to be corrected for gestational length to ensure that the effects are due to nutrition and not prematurity.
However, many studies since have found a significant relationship and a meta-analysis by Shenkin and colleagues indicates that birth weight is associated with scores on intelligence tests in childhood. This relationship has been harder to establish because the issue of malnutrition is often conflated with socioeconomic issues.
Environmental Influences on Intelligence: Intro to Psychology
However, it has been demonstrated in a few studies where pre-schoolers in two Guatemalan villages where undernourishment is common were given protein nutrition supplements for several years, and even in the lowest socioeconomic classthose children showed an increase in performance on intelligence tests, relative to controls with no dietary supplement.
This thus results in abnormalities in the formation of neural circuits and the development of neurotransmitter systems. However, some of these effects of malnutrition have been shown to be improved upon with a good diet and environment. Specifically, the caudate nucleus is particularly affected by early environmental factors and its volume correlates with IQ.
In an experiment by Isaacs et al. When the individuals were assessed later in adolescence, it was found that the high-nutrient group had significantly larger caudate volumes and scored significantly higher on verbal IQ tests. This study also found that the extent to which the caudate volume size related selectively to verbal IQ was much greater in male participants, and not very significant in females.
This may help explain the finding in other earlier research that the effects of early diet on intelligence are more predominant in males. It also found that the cognitive function of males was significantly more impaired by poorer postnatal nutrition.