Intelligence

Well I wanted to write an article on Intelligence because one of my friends always had doubts about few aspects of Intelligence like – Is it determined by heredity? What are the effects of consanguine marriage? Hope this article clears some of his doubts. This article is dedicated to my friend Naveen.

Intellectual functioning refers to the person's general mental capability - their ability to reason, solve problems, comprehend ideas, and learn quickly. This is often measured using a standardized Intelligent Quotient (IQ) test administered by a professional. A person's adaptive skills are the daily living skills that they need in order to successfully live, work and play in the community. Some examples are communication, self-care, social skills, leisure, health and safety, self-direction, reading, writing, basic math, community use and work.

Technically speaking, Intelligence comes from the Latin verb "intellegere", which means "to understand". By this rationale, intelligence (as understanding) is arguably different from being "smart" (able to adapt to one's environment), or being "clever" (able to creatively adapt). A pioneer in the area of intelligence is David Weschler and Francis Galton. In other words of Weschler , intelligence is a person's aggregate ability that makes adequate and purposeful action, rational thinking, and successful and useful interaction with the environment possible. There are various other definitions of Intelligence. Although experts differ on an exact definition of intelligence most agree that intelligent behavior has at least two components: The ability to learn from experience and the ability to adapt to the surrounding environment.

Debate:

Nature Vs Nurture:

The nature versus nurture debate has been a classic controversy among experts for centuries. Though there has been no clear-cut conclusion, there have been various hypotheses. The ‘nature’ side of the debate argues for a hereditarian view of the phenomenon of intelligence: that a person maintains his mental ability solely based on what he is born with genetically. Defending this side of the debate exclusively would be establishing that a person’s environment plays no role in determining his mental aptitude. Conversely, the nurture camp argues that a person’s environment plays a large role in his mental aptitude. This may be the less obvious influential factor on one’s life.

Proof for nature:

One of the simplest research designs for assessing the hereditary vs. environmental influences on complex behaviors, such as intellect, is in the longitudinal study of twins. Monozygotic twin pairs have 100% of their genes in common, and dizygotic pairs only have 50% in common (Province, M.A.1999). For a monozygotic twin there is a correlation of 80-90% on IQ test-- this is true even if they are reared apart. Dizygotic twins have a correlation of only about 50% on IQ tests. Therefore, the overall heredibility of intelligence is estimated at 50-70% (Clothier, J.L.1997).
Research shows that children share 50% of their genes with each of the parents.

Proof for nurture:

Adoption studies have also somewhat shown that a person environment plays an important role in his mental ability. For example, a study done with adoptive children raised in the same house had very similar IQs, given that these children were in no way related genetically.
Several recent US studies have also demonstrated improvements in children's IQ's by improving the lives of infants in disadvantaged circumstances. These studies employed random assignment of children and families to treatment and control conditions. These studies selected experimental families with low parental IQ, low parental education, and minimal financial resources. The experimental group received enriched, educational day care outside the home every weekday from 3 months to start of schooling. The control group received nutritional supplements and pediatric medical care or crisis intervention but no educational day care. Even though the children returned to their home environment every day and spent holidays and weekends with their families (mostly unemployed, single mothers) in poverty-stricken neighborhoods, there were large gains in IQ. This shows that education as a part of an individual’s environment has a huge effect on that individual’s intelligence and mental aptitude.
So there are evidences supporting both the sides. To conclude we can say that, Nurturing has a profound effect on intelligence. The nature-versus-nurture debate is wrongly framed — biology matters and help in shaping young minds, and so does experience. Intelligence doesn't develop in a vacuum. A child's intelligence is being shaped, challenged, and expressed every day by experiences with people, objects, and events — especially when he is an active participant. These experiences are the raw ingredients of intelligence.

Issues concerning intelligence:

Lay conceptions of intelligence tend to differ. Some people see intelligence as a fixed quantity. Either you're smart or not smart. Other people see intelligence as something that is modifiable with work and practice. The best evidence is that intelligence is at least partly modifiable. Because of that, it’s probably more useful to realize that your intellectual abilities can be honed through hard work, education and practice.


Monogenetic Vs Polygenetic:
There is a debate over the issue as to whether a single gene could have a large effect on something, which seems so complicated as Intelligence, or if there were multiple genes involved with each adding a small contribution to the overall encoding of the trait. The research shows that inherited mental attribute is a complex phenomenon that is determined by hundreds or even thousands of genes.

Decline of Intelligence:

This is again a much debated topic. To understand this, we need to differentiate between the two types of intelligence. Psychologists use two major terms to identify different forms of intelligence. Fluid intelligence is tied to biology and deals with an individual's ability to make on-the-spot decisions that are not dependent on experience. Crystallized intelligence is the amount of information a person has absorbed and accumulated from a society's culture over time. Research shows that crystallized abilities remain very high in old age but the fluid abilities decline with age.

Consanguine marriages:

Birth defects have been closely linked to marriages between close cousins and relatives. It has long been recognized that the offspring of consanguineous couples have an increased risk of morbidity and mortality. Contrary to popular belief, conjugation between close relatives by itself does not cause deformities. It simply increases the children's chance of being born with problems. If a couple is related by descent and have an ancestor in common in a recent generation, then the chance that two mutant alleles are inherited by their child is increased, because blood relatives share genes. The number of genes in common depends on the closeness of the relationship. First cousins share about 1 in 8 of their genes, while second cousins share about 1 in 32 of theirs. If there is any problem in your family, both of you are more likely to carry the genes for it because you are family. If you have children there is a higher chance of them inheriting any of those problems. Thus the potential risk increases with consanguine marriages.

Genetic disorders and consanguine marriages:

Frequency of occurrence of genetic disorders was twice in children born to parallel-cousin parents as compared with those occurring out of cross-cousin marriages. Psychomotor retardation (14.3%), primary amenorrhoea (11.2%), and mental retardation (6.6%) topped the list of disorders encountered in children born to consanguineous parents. Cases of phenylketonuria (PKU) were encountered exclusively in children of consanguineous couples. Of the patients having positive family history of genetic disorders, 93% had consanguineous parents.

Risk of mental deformities with consanguine marriage:

1.Psycho motor retardation- RISK –14.3% (consanguine marriage) and 4.9% (non- consanguine marriage)
2.Mental retardation- RISK- 6.6%(consanguine marriage) and 4%( non- consanguine marriage)
3.PKU – RISK- 1.1%(consanguine marriage) and 0%(non-consanguine marriage)
4.Microcephaly (circumference of the head is two times smaller than the average)- RISK 2%(consanguine marriage) and 0.7% (non-consanguine marriage)
5.Klinefelter syndrome (males having XXY instead of XY)-RISK – 1.4% (consanguine marriage) and 0.7% (non-consanguine marriage)
6. Nearly 21% of the mentally retarded (including cases of psychomotor retardation) were born from consanguineous alliances as compared to only 8% from non-consanguineous parents.


Amazing facts:

1.Intellectual foundations are laid by the age of two.
2.Albert Einstein’s IQ score was 186!!!!
3.President George Bush had an IQ of 91 which was the lowest among the Republicans.
4.A 10-minute loss of oxygen supply to the brain will result in neural damage.
5.Cerebellum or the little brain weighs only 150 grams!!!
6.Approximately 20% of the blood flowing from the heart is pumped to the brain. The brain needs constant blood flow in order to keep up with the heavy metabolic demands of the neurons.
7.There is no sense of pain within the brain.
8.The average human adult brain weighs 3 pounds.
9.Higher your I.Q. the more you dream.
10.Japanese research has concluded that moderate drinking can boost IQ levels