Francis Galton was a remarkably intelligent man with an estimated IQ of 170. He believed that all intelligence is inherited and has nothing to do with the environment that we live in and the influence of our home background, including our teachers and our parents. He was the first to note the importance of individual differences; he created the first tests of mental ability, was the first to use questionnaires, and devised the first tests to measure the association between ideas in a subject's mind. He initiated interest in many areas that are now part of psychology, including mental imagery, the role of adaptation, comparison of species, heredity versus environment, and studies of children. He created several statistical procedures to help him analyze his data, including techniques still in use today. He was one of the pioneers of intelligence tests and he was also a founding member of the Eugenics Society in the UK. The belief that intelligence is biologically determined in the make-up of the brain, and therefore to some extent genetically determined, is widely accepted. But a number of researchers over the years have used this idea to advocate social change. Using intelligence as one of their factors, Hernstein and Murray's controversial book, The Bell Curve (1994) argued that differences in IQ scores between racial groups reflect innate biological differences.
Although he said in his book "Hereditary genius":
"I have no patience with the hypothesis occasionally expressed, and often implied, especially in tales written to teach children to be good, that babies are born pretty much alike, and that the sole agencies in creating differences between boy and boy, and man and man, are steady application and moral effort. It is in the most unqualified manner that I object to pretensions of natural equality. The experiences of the nursery, the school, the University, and of professional careers, are a chain of proofs to the contrary."
I think that what he says is not true. I think some of us may have inherited a little more intelligence from our parents than others, but I feel that it is our choices and decisions that influence our intelligence. An example of an experiment of this is when identical twins, who have exactly the same DNA, are separated at birth and put into two different environments.
I think that we cannot believe Francis Galton's ideas were correct because one of his main hypotheses "The Bell Curve" was proved to be incorrect. Evidence to suggest social factors are important in 'intelligence' is strong. The US military tested recruits to assign rank and found that black applicants scored lower than whites. However, analysis of the recruits were found to be due to educational differences; black recruits scored very low until the 1950s, when an increase in score corresponded to improved educational standards for all.
This suggests that environmental influences do affect intelligence but so too does inherited intelligence. Not all individuals are born with the same intelligence and many believe this must have something to do with our genes and the way they interact with the environment. Identical twins are more likely to obtain the same score in an IQ test than twins from two separate eggs that have a different genetic make up.
It is important to remember that genes work by interacting with the environment, so social factors will also influence intelligence. Intelligence tests may be more of an assessment of social factors, such as your educational background.
Better schooling, parenting and increased leisure time for activities are believed to have influenced improved IQ scores across the board. Good nutrition means an individual is able to function well both physically and mentally. Although many believe this plays a role in intelligence, it is very difficult to assess. A balanced diet will provide all the foods required to maintain the correct balance of neurotransmitters.