Is Intelligence Hereditary?

   

This article asks the question, is intelligence hereditary (can it be passed down)? In an attempt to answer this,  scientists have studied whether intelligence is passed down through families for a long time. To do this, they studied intelligence levels based on people raised with their biological parents in comparison with their adoptive parents.  They discovered that genes play a substantial role, accounting for about half of the differences in intelligence among people. They also discovered that genes aren't the only factor in this though—environmental influences are essential for the development of intelligence too. Recent studies suggest that hundreds, maybe even thousands, of genes are involved in intelligence, but we're still far from understanding it completely. Genetic influence on intelligence seems to increase as people grow older, which may be due in part with the stages of the development of the prefrontal cortex.  Understanding the genetic basis of intelligence could help us prevent or improve cognitive problems in the future.

Reading this was rather surprising to me, especially the part that mentioned that children that are separated from their biological parents due to adoption tend to be as similar to their biological parents as those who aren't separated at all. This brings to mind an argument as old as time, is nurture or nature the biggest contributor to the way people behave? Solely based on this article, I would say the way people have a big say in the way they will turn out, but I think when it really comes down to it, we are all born with some instincts that couldn't possibly have been learned. 

Sources

1. https://www.scientificamerican.com/article/is-intelligence-hereditary/

2. https://neurosciencenews.com/intelligence-genetics-brain-22936/ (Alternative Link & Image)

Are you Intelligent because of your Genetics?

 

    In short, yes! Scientists have done studies that have compared twins and adopted children with their families IQ. They tested to see if there was any correlation. There was some relationship between families IQ and their children's, however it was not strong enough evidence to point at one gene or another. Scientists concluded that many genes probably code for intelligence with also strong environmental factors. I think that intelligence is more environmental than genetic. I think that if anybody works hard enough at something that they can succeed as much as anybody else. Maybe it would be more difficult if they lack a natural ability, but I do not think that bad genetics make you unintelligent.

https://medlineplus.gov/genetics/understanding/traits/intelligence/ 

https://www.human-intelligence.org/intelligence-is-genetic/ 

Is Intelligence Determined By Genetics

Intelligence is measured in many ways. Many people assume intelligence comes from genetics, but on the contrary there are studies that show that intelligence is made up of both genetics and environmental factors. Studies have been done to by measuring a person's intelligence quotient, which is abbreviated to (IQ). Scientists ran these various studies and used family related and even adopted children and twins. After doing these studies, it does prove that (IQ) is made up by genetics and environmental. A person's way of living has a huge factor on how a person's intelligence is made up of. A person’s environment and genes influence each other, and it can be challenging to tease apart the effects of the environment from those of genetics. 

https://www.nature.com/articles/nrg.2017.104

https://medlineplus.gov/genetics/understanding/traits/intelligence/

Is intelligence determined by genetics?

    Intelligence is difficult to study due to the fact that there are an ample amount of variables that influence a person's intelligence. There are also different types of intelligence. The different types include the ability to reason, plan, solve problems, think abstractly, and understand complex ideas. Many studies focus on IQ for a quantitative measurement of intelligence. Based off of the article written by Genetics Home Reference, about 50 percent of the difference in intelligence among individuals are from genetics. Scientist's believe that many genes are involved with intelligence.   However, environment has a huge impact on someone's intelligence.

https://ghr.nlm.nih.gov/primer/traits/intelligence
https://www.nature.com/articles/nrg.2017.104

Genes don't just influence your IQ—they determine how well you do in school

A research was done with more than 6000 pairs of twins found that academic achievement is influenced by genes affecting motivation, personality, confidence, and dozens of other traits. The researchers have also shown that a person's IQ is highly influenced by genetic factors. They identified about 20 genetic variants associated with intelligence, each accounts for just 1% of the variation in IQ scores. The genetic variants associated with head size and the volume of the hippocampus is important for learning and memorizing. However, it is been unclear whether the same genes that influence IQ also influence grades and test scores. Thus, by doing researches with twins, whom share the identical genome with each other concluded that there is a genetic basis for the differences in how easy or enjoyable children find learning, rather than their actual IQ. In my opinion, this research is fascinating, due to the result of it is so different from what the society expectation and from what I known. I thought intelligence is always correlated with how much neurons one have or their ability to learned and memorized fast. However, this study proved otherwise, it is due to their genetic variants regarding about the personality which corresponding to the feeling of enjoy the subjects that one are learning.
Reference:
Link 1
Link 2

Genes Influence Human Intelligence

Human Intelligence 

 Scientists discovered that genetic plays a major role in intellectual behavior. Recent studies, show that 40% of human intelligence is inherited in our genes. The two networks known as M1 and M3 gene are essential for understanding the development of neurological disorders such as epilepsy, autism and schizophrenia. " We know that genetics play a major role in intelligence but until now haven't known which genes are relevant." Hence, this could be a possibility for scientists to manipulate a different set of genes that are relevant to human intelligence. Which could be a possibility for doctors and patients to find better treatments for neurological disorders.  

I think this article was interesting because researchers have the potential of understanding how mutated genes are associated with neurological disorders. It will be a new insight for scientists to gain knowledge about cognitive disabilities and provide early prognosis for individuals with learning disabilities. This might help understand how autism spectrum disorder can be a possible cause of mutation in the genes.

College Graduation May Be Partly Determined by Your Genes

Two years ago scientists decided to delve into the question: Is intelligence, or academic performance, written in our genes? Scientists isolated clusters of genetic patterns that seemed to be associated with higher levels of education, by data mining the genomes for 100,000 individuals. Although they did not identify a gene for specifically education or intelligence, they did find that people who had completed more years of schooling were more likely to share certain genetic variations, compared to the individuals who had dropped out of school earlier. By studying pairs of siblings, Ben Domingue of Stanford University cleared away the confounding factors. For twins, small differences in their genetic makeup stand out because so much is similar. Researchers have also found that within families, an adolescent with a higher polygenic score than their sibling actually tended to go on and complete more schooling. A polygenic score is a measure of how many of the genetic variations associated with educational attainment a person has in his or her genome. Domingue explained “The sibling with a slightly higher polygenic score continued in school for only one third of a year longer, on average, than the sibling who had a lower score.” In explaining that, Domingue also including that there is evidence to suggest that genes are causing differences in educational attainment, although it is a very small amount. Socioeconomic factors remain much stronger. As an example, having a mother who graduated from college was associated with an additional 1.7 years of schooling. 

Within their research, scientists found that family environments may expand small genetic differences between siblings and that there is no relationship between a sibling’s birth order and his or her polygenic score.

Domingue will continue to research and explore how the genetic variations for educational attainment may develop into personality traits that lead children to become good students. He wants to figure out if students with high polygenic scores are more sociable and finally, wants to explore the interaction between genes and the environment to learn if there are things that schools or teachers can do to moderate genetic antipathies to education. 

This research will continue to go on for many years and it won’t be for many years after that, that scientists identify the genetic mutation for attention deficit hyperactivity disorder (ADHD) for example. 

In some academic articles, the data is broken down to show how the types of races differ. To avoid misleading readers, Domingue left that out of the article and stated “The most contentious areas has to do with race,” but also included, “I have zero interest in trying to explain between race differences in education achievement, I don’t think there’s anything there.” 

Original Article