Heredity Versus Environment
Heredity Versus Environment
A major debate within psychology is whether it is nature or nurture which influences people; the way people act and behave, cognitive development, and what we look for in a partner are just some aspects of the debate. Nature supporters, or Naturists, believe that our behaviour is down to genetics and is inherited from our parents. They believe that everything about a person is decided at the moment on conception. Whereas nurture supporters believe that people learn their behaviour from the environment, their upbringings and the surrounding influences; such as friends, peers and work colleagues. There is lots of research, studies and evidence to support both arguments on a variety of subjects.
The nature argument is often used in court cases to describe uncharacteristic or deviant behaviour. Humans are often related to as animals as this is believed that people evolved from, Charles Darwin is a leading figure in this side of the argument. He pioneered his theory of evolution, and it is widely accepted that humans did derive from a ‘common ancestor’, therefore do have instinctive behaviour, and traits about their personality (Allaboutscience, 2014). A real life example of this would be a baby, who is unable to communicate, and has little understanding of the world; however still show signs of fear if they were to hear a loud noise.
Nurture supporters believe that a person’s upbringing is a major factor which influences people in later life. A real life example of this would be serial killers, when studied, they were often subject to horrific abuse as a child and they blame this for their inabilities to conform to society’s norms and commit dreadful crimes. This is supported by a psychological study Bowlby’s 22 juvenile thieve study; people commit crimes due to what kind of upbringing they received. The lack of a secure attachment with their primary care giver (McCloud, 2007).
The term gender refers to whether a person socially and culturally class themselves as male or female, and which role they choose to live their life by in society. Rather than the term sex; which is what’s chosen biologically by genetics whilst in the womb (Who, 2014).
Psychologists look at gender difference within the nature/nurture debate; to see if genetics or environment factors play a part in what makes genders behaviour and act differently. There are stereotypical gender roles in society; examples of which are that females are seen as maternal caring and loving people whereas males are seen as aggressive, dominate, and the breadwinners. Scientists know that there are biologically difference between genders; such as hormones, and chromosomes, these are scientifically proven. Also they have been shown to majorly impact a person’s behaviour, for example the male hormone testosterone is contributor to aggressive behaviour and is the reason behind why males have more muscle mass supporting the nature perspective.
Whereas nurture supporters believe that gender differences come from the environment, for example, children are dressed in colours which are stereotypical for their sex; blue for a boy and pink for a girl. This is further supported by the self-fulfilling prophecy; that if a person is told that they are something (male or female in this case) they will eventually believe this which will affect their behaviour. Interactionism is a term used to describe genetic gender differences which are influence or modified by the environment.
Mary Mead conducted an experiment supporting the nurture argument of gender differences in 1935, where she studied three different tribes; Arapesh, Mundugumor, and Tchambuli. The arapesh were non aggressive, with a caring attitude towards children. The Mundungumor were aggressive and cold towards children. The Tchambuli was the tribe were the males were submissive and passive. The results were that Mead found a slight pattern in male and female behaviour across different cultures however there were a lot more differences. Supporting the nurture argument as in Mead’s study two tribes showed role reversal; in one tribe the males were dominate and aggressive, whereas in another the females were, and the males were submissive. Also females being cold and uncaring towards children; this showed psychologists that it can’t be instinctive or genetic that women must have maternal tendencies. This therefore shows interactionism in western society. A criticism of this study is that all three tribes where in close proximity therefore are the sample could be said to be culturally similar (Benson, 2005).
Buss et al in 1990 conducted a study which found that males are more aggressive than females regardless of culture. They found cross cultural similarities between the genders; these were in how people look for a perspective reproductive partner. Buss et al found that men preferred youth and attractiveness whereas women looked for wealth and status. This study supports the nature debate as Buss et al studied a wide and varied sample of people, and some people believe that these results can still be seen today in the western world.
Another psychologist credited for his work in regards to this debate is Bronislaw Malinowski; he carried out a research project in north-western Melanesia in 1929. Malinowski like Mead studied tribes however he looked at their sexual behaviour and concluded that sexual behaviour dominates every aspect of life regardless of culture, which further supports the nature debate.
As with all studies, there are things which may affect the results of the research. With studying tribes there could of been a communication barrier, between the researcher and the participating tribes which would effect the results. The gender of the psychologist performing the study could influence the results as they could be said to be bias; as they may favour there own gender. Also the presence of a researcher in a person’s everyday life may alter the way that person behaves and acts around them.
To conclude, there are lots of gender differences, some appear similar across the world whereas others appear to be culturally connected. In relation to the nature/nurture debate, there are arguments and studies to support both sides, and will always be a conflicting argument throughout psychology.
Critically evaluate some evidence which offers support for the role of ‘nature’ in the heredity-environment debate on intelligence
One disagreement people have in the topic of heredity versus environment is about the subject of intelligence; are people born an intelligent person or is this acquired over time, when information is learned and absorbed into a person brain.
Intelligence is defined as a ‘manifestation of a high metal capacity’ (Dictionary, 2014). A commonly used test to assess a person’s intelligence is a series of questions called an IQ test; the higher the IQ score the more intelligent a person is believed to be. Francis Galton in 1869 studied the subject of intelligence and since then lots of psychologists have been interested in the debate and there have been many studies conducted (Malim & Birch, 1998).
In support of the nature debate, there have been a lot of experiments conducted on siblings, including twins studies, and cousins. Twins can be categorised into two groups; monozygotic (MZ), and dizygotic (DZ). Monozygotic twins are ‘identical’ and share the same genetic information as they were produced from one egg, whereas dizygotic twins are produced from two separate ova and have the same genetic information as two children with the same parents (Malim & Birch, 1998). As with all studies in this debate, these have been heavily criticised by supporters of the opposing arguments, this assignment will evaluate some of these. The main criticism of the majority of IQ studies is that all the participants are children or adolescents.
Newman et al in 1937 embarked on a ten year research project studying 100 pairs of twins, 19 of which were adopted MZ twins; 7 males and 9 females. These adopted twins had experienced different upbringings so Newman wanted to see how this affected their intelligence (Twin Studies, 2014). The results were that the IQ of monozygotic twins was higher than that of the dizygotic twins which Newman studied. They also showed that the IQ of twins reared together was higher that if the twins had been separated after birth. However a major criticism of this study is that Newman enrolled the twins that he studied on similarities to ensure that the twins he studied were MZ, as at the time the technology wasn’t available to scientifically prove whether the twins were identical or not.
Also the sample of twins which Newman et al studied has been said to be biased, due to the expense of conducting the experiment; Newman had to pay for the sample to travel and stay in lodgings in Chicago. The results could then be flawed as twins may have acted in a certain way to be chosen for the study in order to go on an all-expenses paid holiday during a time of great depression across America. It has also been proven that a pair of twins from Newman’s sample group were raised in the same town and even attended the same school (Benson, 2005).
A more recent twin study was conducted by James Shields in 1962; Shields took a sample of 44 pairs of identical twins who had been brought up apart from each other. Shields enlisted these twins by a television advertisement and wanted to find out the correlation between their IQ results. The findings were that the correlation of identical twins reared apart was higher than the non-identical twins reared together; who Shields also studied. This study is often criticised due to the method the participants were enrolled onto the study; twins were put forward to the study as they looked alike, they may not have necessarily of been proven to be monozygotic or identical. Another flaw is that although Shield’s claims that the twins were brought up separately, they were often raised by members of the same family, lived locally, and went to the same schools. It is reported that one pair of twins, lived next door to each other. Despite the flaws this study is often seen as one of the strongest twin studies in psychology in relation to IQ again supporting nature (Firth, 2009).
Other than twin studies, some psychologist studied intelligence and how it correlates with differently between different ethnic groups and races in society.
Arthur Jensen was one of these, in 1969 he analysed the differences in IQ results between different races, and published his results, which sparked outrage across america. Jensen’s devised an intelligence test for children, and his pupils to sit the test from the school which he was a professor at. The test comprised of two parts; level one abilities or associative learning and level two abilities or conceptual learning. The results were that the ‘white american’ students performed better at the task two abilities than students of other races (Telegraph, 2013). Jensen concluded that intelligence was 80% inherited, as he believed this from his results that a child’s ancestry was the reason that some children scored poorly on the test. This leading to him to believing that intelligence is a factor of genetics and is passed on through generations. However there is an opposing argument, that this study also supports the nurture debate, as it shows how different cultures are effected differently. For example, the caucasian children would of come from a higher social class than the ethnic minorities; therefore it was the environment and peers which affected their mental ability.
The ethical issues involved with this study are evident as Jensen incited racism by publishing these figures. This could of also led to violence, and sparked hatred within the community and across american. Also some students could of been favoured over others, as they would be seen as clever, therefore received priority treatment, as proven in Rosenthal & Jacobson’s study in 1968. Jensen completed his test in 1960’s america, which was a hostile time, in particular within regards to race segregation, with the speech and assassination of Matin Luther King.
Hans Eysenck was a German psychologist who is also credited for his work in relation to intelligence and race (Cherry, 2014). He wrote a book called: The IQ argument: race, intelligence and education, based on these studies and summarised the results. This book claims that ’80% of variability is inborn’ (Benson, 2005). Hans was also criticised as his views also focused on the differences between IQ results of blacks and whites, rather than treating people as equally as individuals. Eysenck believed it to be fact that white people had a higher IQ and set about telling the world. Some people didn’t agree with his views which involved him being attacked on numerous occasions and becoming a hated public figure.
In conclusion, there are a lot of studies in psychology in regards to the nature/nurture debate, on a whole array of topics. Intelligence is only one of these. Criticisms are prevalent throughout all these studies as it is a debate which people just can not agree on, and everyone has their own opinion.
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