“Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I ‘ll guarantee to take any one at random and train him to become any type of specialist I might select – doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors.” – John B. Watson.
Generally, using the terms “nature” and “nurture” as a suitable catch-phrase for the roles of genetics and environment in human and animal development dates way back to 13th century France. Some scientists feel that people act according to genetic inclinations or “animal instincts.” This is the “nature” theory of human behavior. Other scientists suggest that people reason and act in certain ways because they are taught to do so. This is the “nurture” theory of human behavior.
The increasing understanding of the human genome has made it clear that both parties of the controversy have merit. Nature gives us inborn abilities and traits and it takes these genetic propensities and molds them as we learn and develop . The “nature vs environment” argument is still on, as scientists debate over how much of who we are is shaped by genes and how much by the environment.
The human genome has been proven to determine the different traits that we have, majorly on the physical characters like eye color, hair color, ear size, height, and other traits. However, we are not certain about whether our abstruse characteristics like intelligence, personality, preferences, sexual orientation are gene-coded in our DNA, too.
Also, the behavioral genes are somehow proven to exist when you observe fraternal twins. When fraternal twins grow up in different environments, they may respond and behave to certain situations as though they were reared together.
The nurture theory insists thatalthough genes and heredity may influence abstract traits, environmental factors make the major contribution to human and animal behavior. This includes the use of conditioning in order to induce a new behavior to a child, or alter an unlikely behavior being shown by the child. John Watson, one of the leaders of the Nurture campaign, once said that he can be able to train a baby randomly chosen in a group of 12 infants, to become any type of specialist he wants. He stated that he could train him to be such regardless of the child ‘s potentialities, talents and race.
Even though fraternal twins raised apart often have remarkable similarities, still the differences in environmental influences may lead to several variations in the way they behave.
We are still left in our dilemma: Are we born this way, or do we act in accordance to our life experiences? The nature vs environment controversy goes on and on, and although it is a fact that we have traits that are predetermined by our genes, we can still choose who we want to be as we travel through our lifetime.
Over time, psychologists have tried to observe the relative amount contributed by genetics or environmental factors to diverse human behaviors.
The frequently asked question is whether human and animal behavior is determined by the person’s genetic inheritance or is the behavior determined by upbringing .
The concern in this question resulted to what is called the Nature Nurture Controversy.
Many researchers took extreme positions in this issue, while some researchers exercised on exclusive roles or genetic hereditary, others took the opposite extreme by denying biological contribution and emphasizing learning and experience .
John Locke . He posits that new born children are like ‘’tabular rasa’’ or ‘’blank slate’’ which is an example of a white board or black board, and anything written on this board can only be attributed to learning and experience.
According to this view, nature contributes nothing to human behavior apart from providing a life body. Although this position was later disproved, the idea had enormous effect in philosophy, politics, and psychology.
The opposite side of this debate holds that humans are born with complete genetic instructions that determine their response to every situation.
One of the strongest argument in support of this position was Wilhelm Von Heibnits. His main argument on position is that we are the way we are born, which he based it on the belief that genes and hereditary must contribute to human behavior, this position is invalid because there is no particular or one gene responsible for behavior. Although genes act at a molecular level in the development and maintenance of the structures that has consequences of behavior, the inheritance of behavioral traits follow a multi-factorial pattern which involves actions of many genes and interactions between heredity and environment.
In modern times, researchers have demonstrated that both hereditary and environment play a role in behavior through their interactions. Human behavior is therefore a result of the complex interactions between hereditary and environmental factors.
HOW DOES THIS ISSUE HELP US IN UNDERSTANDING HUMAN AND ANIMAL BEHAVIOURE?
How do genes and the environment come together to shape animal behavior? Both play important roles. Genes capture the evolutionary responses of prior populations to selection on behavior. Environmental flexibility gives animals the opportunity to adjust to changes during their own lifetime.
The early men did not really get the point of inheritance, of DNA, or of the translation of genetic information into morphology, physiology, or behavior. But they intuitively understood that inheritance shapes behavior. By controlling mating, herds and flocks of animals useful to humans were domesticated. The domesticated animals which are cattle, horses, and dogs actually behave in a very different way than their wild fore fathers or ancestors . Selective breeding was a useful insight in the history of humans, even if the science was not understood until the Darwinian and Mendelian revolutions in the nineteenth century.
In this recent times it is easy for us to be able to recognize that both genes and the environment influence behavior, and the scientists that study behavior focus on the interaction between these two factors. Genes, through their influences on morphology and physiology, prepare a framework with which the environment acts to shape the behavior of an individual or animal. The environment can affect morphological and physiological development; in that case behavior develops as a result of that animal’s shape and internal workings. Genes also designs the scaffold for learning, memory, and cognition, remarkable mechanisms that allow animals to acquire and store information about their environment for use in shaping their behavior.
Instinct and Behavior
Instinctive, or hard-wired (i.e., by definition, genetically determined), behavior captured the interest of Charles Darwin, and later, of the ethologists such as Niko Tinbergen. Instinct implies that a behavior is performed without thought and cannot be modified by learning. Examples of instinctive behavior include simple behavioral patterns, displayed in response to a specific stimulus or within a specific context. A cockroach flees to the protection of a dark nook when a light is switched on. A dog may circle on its bedding several times, as if it were trampling vegetation, before settling to sleep. A rattlesnake will strike at a moving, mouse sized, warm object. In none of these cases does the animal engage in learning or thought when shaping its response. Genetic (innate) information best determines behavior when a species’ environment varies little from generation to generation, or in communication when unambiguous messages need to be sent and received
Similarly, many of the signals used in animal communication are innate, produced the same way by all members of a species. The constancy that comes from having the signal and its interpretation genetically encoded makes the message unambiguous. Combinations of facial expressions, hair erection, and tail posture give dogs (to other dogs) a universal set of messages. Other animals use combinations of genetic and learned information in forming their signals. Some birds can produce elements of their songs without ever having heard another bird sing, but require hearing songs during development to reproduce the song of their own species correctly. This last example demonstrates how innate components can be used as building blocks for modifiable behavior, but animal behavior can be innate, reflecting a strong genetic basis.
Imprinting and Development
Imprinting involves the ability to learn a specific essential piece of information at the right stage of development. Openness for learning through imprinting is restricted to a short time span, called a critical period. The most famous example of imprinting comes from Konrad Lorenz and his geese. He found that goslings learn to recognize their mother (and to tell her from other geese) very early in life. By substituting himself for the mother goose at the right developmental stage, he could get the goslings to imprint on him, and faithfully follow him wherever he went. The openness of goslings for learning a leader, even if it does not resemble a goose, is intriguing. Imprinting demonstrates how genes can largely shape a behavior, but that evolution can create a window for learning important information about variation in the environment
Imprinting provides an opportunity to learn key variable components in an environment while retaining largely innate behavioral patterns. More flexibility may be shown in the development of food preferences, as food availability can vary from habitat to habitat, or from season to season. Insects may imprint on the chemistry of the leaves they eat as caterpillars; when they become adults they then choose to lay their eggs on plants with a chemistry that matches the leaves they ate when young. This insures a suitable diet for the next generation. Young birds and mammals often learn food preferences based on food shared by adults, on observations of feeding preferences of adults, and on sampling possible food items.
Another form of learning involves aversions, which can develop at any point in any animal’s life. Birds and mammals develop lifelong aversions to specific foods that contain poisons that cause sickness (such as monarch butterflies). In contrast, some preferences and aversions appear to be innate, or at least to be driven by physiological needs for certain nutrients, such as salt.
Genes and Environment in Human Behavior: Sociocultural Influences.
Quite often humans worry that their behavior might be completely controlled by their genetic make up, meaning that one might be involuntarily compelled into poor parenting, violent behavior, or drug addiction. Most human cultures also has strong beliefs in self-determination and free will, as well as the ability of humans to be able to differenciate the right from the wrong and to make choices about the appropriateness of their actions. Heated arguments among biologists, philosophers, and ethicists over the relative roles of genes and behavior in human behavior have brought no simple resolution. The and will continue to fuel controversy, even as more is discovered about the genetic and evolutionary bases of behavior.
TWIN STUDIES AND ADOPTION STUDIES
One way to determine the contribution of genes and environment to a trait is to study twins. In one kind of study, identical twins reared apart are compared to randomly selected pairs of people. The twins share identical genes, but different family environments. In another kind of twin study, identical twins reared together (who share family environment and genes) are compared to fraternal twins reared together (who also share family environment but only share half their genes). Another condition that permits the disassociation of genes and environment is adoption. In one kind of adoption study, biological siblings reared together (who share the same family environment and half their genes) are compared to adoptive siblings (who share their family environment but none of their genes).
The nature side of this debate emphasizes how much of an organism reflected are s biological factors. But, on the other hand genes are activated at appropriate times during development an the basis for protein production. Proteins include a wide range of molecules, such as hormones and enzymes that act in the body as signaling and structural molecules to direct development.
Although they may seem alternate and antagonistic in constitution, nature and nuture,work hand in hand in defining human and animal behavior. Many aspects of human behavior, which can not be explained by genetic and behavioural analysis of parents can be explained by evaluating the influences of the individuals social and physical environment.
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