Tuesday, 14 June 2005

Nature, Nurture and the IQ

Published on The Himalayan Times, 14th June 2005


Everyone wants to be more intelligent. Everyone wants to get more marks in mathematics and pass interviews easily. But intelligence cannot be developed within a few days. It is also something inherited as genes that you are carrying and is governed by multiple environmental factors.

In many cases, it is found that there is difference in intelligence level among members of the same family, growing in the same family environment. In other cases, family members or even twins reared apart and growing in different environments possess similar levels of intelligence.
Yet another research carried out in some identical twins on the basis of IQ tests, it can be safely concluded that social and educational environmental differences may strongly affect intelligence despite genetic similarities. In some experiments conducted, a particular pair of twins who were reared apart differed by 24 IQ points; one completed college and became a schoolteacher while other did not finish school. But, this may be also have happened due to lifestyle choices.

Another pairs of twins reared apart difference only by 1 IQ point although one was raised by a well to do physician while a truck driver raised another. This finding sows that the identical twins reared apart do not achieve the same differences in IQ scores. It also points to the possibility that the genetic similarities influencing that portion of intelligence reared in this fashion are not completely thrown off track by environmental differences.

Existence of genetic factors can also be measured in another fashion. The closer the relationship between two individuals, the more similar their IQ test scores, Thus the IQs of children and their natural parents are more closely correlated than the IQs of children and their foster parents. At the same time, however, individuals with the same degree of relation who were reared together show more similar IQ test scores than those reared apart. Therefore it is found that both genetic and environmental factors play a role in intelligence.
Some factors that affect intelligence are as follows.

1. Size of family

A number of studies have shown that greater the number of children in a family, the lower the IQ level per child. The IQW level depends to some degree on the attention given to an individual during his development and children in large families usually have less opportunity of getting adequate attention. More interestingly the particular birth order of a child in a family is believed to be associated with intelligence. It is found that the first born child achieves better IW scores than his later born siblings. The reason is still unknown and it can hardly be caused by basic genetic differences.

2. Cultural effects
IQ differences have been shown to exist, up to a certain extent, between regions in a country and occasionally between religious groups and races. A number of instances are known in which IQ scores have significantly increased when children were given social and educational opportunities unavailable to their parents. This is termed as cultural modification. At the same time, institutionalized youngsters living under poorer social and physical conditions often show gradual decline in IQ performance. A comparative increase of approximately 50 IQ points have been observed among orphans who were adopted or received special enrichment before the age of two.

3. Early environment

The development of the perceptive and problem-solving skills that are reflected in intelligence sores often depends up on stimuli and encouragement that infants and young children receive. It is known that experimental animals deprived of stimuli during early ages will show intellectual retardation. In humans, the early, stimuli depend on the mother.

4. Diet

It is seen that protein deprived females will produce offspring with a reduced number of brain cells. This effect is also accompanied by kidney deficiencies and other severe body difficulties. Therefore, dietary deficiencies caused by social and economic factors play a role in IQ.

The tests on relationships between IQ scores based on family size, birth order and social groping were performed during 1963-1966 on about 40,000 males in Netherlands, all 19 years of age who were examined to determine their fitness for military duty.


Thursday, 5 May 2005

Emotions and Effects

Published in the Kathmandu infotiser on May 2005. The published version might have been edited. 

We wake up in the morning and gets ready for, most probably the beautiful day. We fall sick, get depressed, or be happy, and all over the day and night we are always entrapped with lots of happiness, joys, pains, grieves, pain, excitements, etc. Many of us are busy with memorizing hundreds of English word meaning or mathematics formulae too! But have you ever imagined of your inside body during these emotional or mental status?

Love

We often get infatuated or fall in love. This is the buzzword among always in all walks of lives. Our body understands love through dopamine, a chemical secreted by certain nerve cells and is a type if neurotransmitters. It is responsible for pleasures, affections and loves. Moreover, your short-lived passionate love is due to the accumulations of phenyl ethylamine in your brain.

Suicide

We often hear of incidents of people committing suicide. The scientists have found that the suicidal tendencies are due to the actions of the chemical (neurotransmitter) called serotonin. Scientists noticed that the monkeys in the African jungle committed suicide and when experimented, they found that they had high level of this chemical secreted by their nerve cells.

Depression

More than 90 percent of the people suffer from any form of depression in their life time at any stage of their life. The depression is caused due to the hormone called epinephrine or adrenaline. This hormone is also responsible for anger or sudden happiness etc.

Memory

Memory is of two types - long term and short term. A person with good memory is found to have a larger hippocampus, a part of the central nervous system. But this part is increased on the basis of our labor practices in memorizing different things in daily lives. Interestingly, taxi drivers are found to have larger hippocampus than that of the normal people as they generally have to remember the entire map of the city. While memorizing things, there is a secretion of the chemicals called glutamate. Our brain is 14 hundred times more complicated than that of the entire telephone network of the world. Therefore, it depends or our daily life activities, health or labour in developing memory. Brain has immense capacity for memory than that we can imagine.


Programmed cell suicide

Not only human, even the cells in our body are found to commit suicide due to various reasons. When the body suffers due to severe diseases such as cancer on any part of the body other cells are also gets affected. In these cases, even during the injuries, the cells in the body program together to commit suicide called programmed cell suicide or apoptosis. But don’t think if our cells can suicide, why can’t we?

Smoke addiction

Have you ever heard of genetic causes of smoke addictions? Scientists have identified a gene called SLC6A39. Persons lacking this gene in their body generally find difficulties in quitting smoking. But don’t blame your genes only if you can’t stop smoking.

Caffeine, the chemical in the coffee is found to increase the firing of the neurons, which activates our brain. Thus, people take sips of coffee when they generally get mentally tired due to hectic official work.