Human Intelligence has always fascinated us into delving deeper into the mystery of human sciences; to seek and research truths about intelligence levels. Although science has brought to light that human intelligence is multi-factorial, it has no doubt enlightened us about the role that genetics plays too in defining our intelligence.
A gene is the primary unit of hereditary for everything that is living. Genes contain innumerable amount of information which makes them the building blocks of basic functioning in the living world, be it animals or plants. Genes pass on information or traits from parents to offspring and are instrumental in making an offspring similar to either or both of the parents.
Human Intelligence may be described as the ability of a human being to acquire and apply knowledge in general. That would mean that a lot depends upon the environment, the language a person is exposed to, the culture of a particular place and various other factors like socio-economic background and benefits of education. So in essence, general human intelligence would be the ability of a person to use deductive logic and abstract thought.
While intelligence is dependent on multiple factors, the importance of genes alongside it should not be ignored. An off spring from normal parents of diverse backgrounds usually has a stronger and healthier gene pool. Whereas, an offspring with parents from the same family line interbred for many generations within the same gene pool has a much weaker set of genes which affect the overall intelligence of that individual. This is true in case of hereditary related diseases affecting the growth and functioning of the brain related to intelligence.
Biological studies have shown that the size of the brain or the size of specific areas of the brain is one of the many factors determining intelligence. This could be dependent upon the gene required for proper chromosomal distribution and growth of brain cells. Usually this is controlled at the time of birth or infancy and is not noticed until the child grows a bit. Slower growth of the brain results in a smaller size of the brain and also reflects a lower IQ.
Let us take for examples a study done on a group of isolated Pakistani families in Yorkshire. This group of families interbred, and produced or showed strong evidence of homozygosity. Homozygosity is the state of possessing two identical forms of the same gene, one each from either parent. In this study, those Pakistanis who suffered from a disease called microcephaly were found to possess a set of identical genes inherited from both parents. This ailment resulted in a slower and smaller brain growth that hugely affected the intelligence of that person, showing that person to be of much lower General Intelligence.
It is no secret that human intelligence is influenced by many factors; nonetheless, the most dominant among them is the genetic makeup of a person. Gifted parents generally give rise to gifted individuals and the making of a genius is no mystery. It is the precise combination of genes whether through natural selection or a genetic accident. Genes provide the building blocks for intelligence and affect the way human intelligence takes its course. Genetics, in fact, goes a long way into determining and defining the people we are today.