Unit 8 Nature and Nurture
Useful Information
―Nature and nurture‖ is the catchy and rather poetic term used to evoke the two main sources of factors that influence the physical, psychological and intellectual characteristics of any human being. ―Nature‖, in this case, means everything a person inherits genetically. Originally, the verb ―nurture‖ was chosen to describe the home environment and the influences parents had on their children. In a broader sense, ―nurture‖ refers to the general social environment which includes such things as family influences, peer influences, and educational experiences.
Which has more influence on us, our genes or our environment? How do people become who they are? These are questions that have intrigued educators, psychologists, and geneticists for decades. Over the years, various experiments and studies have been carried out in an effort to determine the relative importance of heredity and environment. Although it is fairly easy to see how our genetic make-up affects physical characteristics such as hair color, bone structure, and facial features, it is far more difficult to measure the impact of parental behavior on the development of personality, for example.
One of the best-known studies on nature-nurture issues was carried out by scientists at the University of Minnesota. Their research on identical twins raised apart suggests that genes play a major role in shaping both personality and intelligence. Some critics of the Minnesota study feel that the social environments of the twins raised apart were too similar to really make conclusive observations feasible. Ideally, the Minnesota researchers should have had twins raised in different cultures and in totally different social classes.
Other studies have stressed the influence of parental verbal behavior on the intellectual development of children. In other words, the more parents talk with their children, the more they are likely to enhance their children’s communication skills. The same studies also showed that socially and financially deprived working-class families were much less communicative than professional families.
A recent study carried out by the Colorado Adoption Project on a large number of adopted children has shown the preponderance of genetic inheritance with regard to personality and intelligence. Other studies have stressed the importance of factors outside the home, such as neighborhoods and one’s peers.
The debate over the relative importance of genes and environment is likely to continue until additional major discoveries are made in the field of genetics. Perhaps some day, the genes for shyness or for gentleness, for example, will be isolated. For the moment, common sense and personal experience tend to suggest that nature and nurture are both important, each having a greater or lesser effect, depending both on the complexity of the gene and the conditions of the environment.
More for the teachers:
How do you live?
We all live in different worlds. Nobody can claim that their life has been the same as yours. You might be wealthy or poor, a megastar, or an anonymous face in a city of millions. You may have an older brother, be an only child, have mixed race parents, live on the sunny side of the street…or in an igloo. Your genes make you unique, but so does your life. It is different from every other human life on earth.
Different beginnings
From the moment you were conceived you have been dealing with unique surroundings. You may have had quite a different nine months in the womb compared to that of your brother or sister. Do stressed out mothers-to-be produce agitated babies? A link has been noticed and it’s just one sign that our different experiences count from very early on.…and once you are born then just about anything can happen. And almost
everything that occurs during your childhood and adolescence could be having an impact on your health, your career and the relationships you are forming today.
Blame it on the genes?
Your genes in combination with your early experiences of life are having an enormous impact on you. From how many calories you require to maintain your weight to your musical skills and talents, both your inherited genetic code and your environment are playing a part. So how do we know what to blame our genes for? In certain instances it is very clear-cut. Certain diseases are caused by a single gene. If you have a gene for cystic fibrosis there is nothing you can do to cure the disease although much can now be done to relieve the symptoms. Eye Color too is a product of our genes and can be changed only in appearance with contact lenses.
In most cases though, the role our genes are playing and how powerful their influence is is unclear. Your weight, intelligence and personality are influenced by many different genes but also by your environment. Scientists are only just beginning to understand the role our genes play in these very
complicated areas. Twins Biology
There are two types of twins, the identical twins called monozygotic and the fraternal twins called dizygotic. So the term twins just indicates two children born together. A twin birth occurs every 100 normal births. In all cases of twins there is a genetic predisposition: in some families twin births are particularly frequent.
Identical Twins \
Identical twins are born from the same egg which splits in two after conception. This is a rarer case that occurs in 30% of twins. These twins have identical DNA and, therefore, they are physically almost identical and must be of the same blood group and sex. In this case usually the two fetuses share the same placenta (胎盘) but have different amnions (羊膜). In some cases they can have even a separate placenta or share both the placenta and the amnions, only in this last case malformations such as Siamese twins can occur.
Fraternal Twins \
Fraternal twins are born from two different eggs and develop separately in different amnions and different placentas, sometimes in the same placenta but the amnions are always different; they have different DNA so they can be of different sexes and can have different blood groups. Fraternal twins are more common and occur in about 70% of twins. Fraternal twins are commonly called ―false twins,‖ because from a genetic point of view they are like brothers or sisters, only they are born at the same time.
Part One Preparation
1. Talking about Twins Samples
1) I knew a set of twins in my class in the middle school. They looked alike and usually dressed alike so we often got them mixed up. They were very close to each other and could exchange their ideas quickly. But they had quite different personalities: one was shy, quiet, and self-conscious while the other was self-confident and optimistic.
2) I think it’s because there aren’t many twins around us. People are always curious about things that they rarely see. Another reason for their curiosity is probably that twins resemble each other, which is very unusual among other people.
3) — They must be proud because they are different from others.
— They may feel happy because they can enjoy each other’s company at home. — They may feel lonely because it is difficult to make friends with other people. — They may feel bored and discouraged because every day they will see the mirror image of themselves.
2. Nature, Nurture or Both
1) Nature and nurture: A person can have natural talents, but mastery always takes some effort. You have to try to succeed.
2) Nature: No matter what the hairdo (hair style) is, their hairlines stay the same. This trait is due to the genes that the mother passed on to her son.
3) Nature: There’s nothing wrong with Julie’s nose. Some people have the genes to smell freesia, others don’t.
4) Nurture: Are you wild about mysteries? Adventures? Biographies? Your tastes may be determined by the books that are available in your home or school.
5) Nurture: Somebody’s favorite clothes and color can change as quickly as the cover of a style magazine. You might say it’s due to the JEANS, not the GENES.
6) Nature: Look at their mother’s earlobes. Genes determine whether a person’s earlobes are attached or detached.
7) Nature and nurture: Your personality isn’t determined only by genes. There are a lot of other factors that make you who you are, such as where you live and the people you meet.
8) Nature and nurture: Practice makes perfect! Melissa earned her position as class champ because she uses her athletic ability and works so hard.
3. What makes us who we are?
1) expected 2) conclude 3) account 4) nurture 5) argues 6) myth 7) predetermin 8)react 9) consequences 10) revolution11) between 12) creature
Part Two Reading-Centered Activities In-Class Reading
I. Pre-Reading Sample
The conclusion is not justified because the sets of twins studied shared not only the same genes but also the same environment. The similarities are not due entirely to genes since environment also plays a role.
II. Passage Reading
Words, Phrases and Grammatical Points
1. history (l. 14)
The word is used here as a countable noun, meaning ―a record of something that has affected someone or been done by them in the past‖. We have phrases like medical/employment/career, etc. history.
I feel like a part of my history has been taken away. 2. infancy (l. 19)
The word is often used in its figurative sense, meaning ―the beginning or early period of existence‖.
I) Research in this field is still in its infancy.
II) Tourism on the island is still very much in its infancy. 3. remove (l. 25)
The word has several meanings. The major ones are listed below. 1) take away (from a place) or take to another place I) The paintings were removed to a museum.
II) As soon as the cake is done, remove it from the oven. 2) get rid of
I) Instant publication would have removed suspicion.
II) Doctors have decided to give her an operation to remove a tumor in her stomach. 3) dismiss
I) All senior officers involved in the coup will have to be removed. II) They made an attempt to remove her from the General Council. 4) removed from: very different
I) What you say is far removed from what you said before.
II) His ideas on foreign policy were far removed from those of the Government. 4. prove (l. 34)
The word here means ―turn out to be‖.
I) He proved himself (to be) an amusing companion.