Roles Played By Heredity and Environment on Intelligence

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Roles Played By Heredity and Environment on Intelligence

Introduction

Behavioral Genetics Behavioral geneticist's uses family, twin and adoption studies as a basis for their argument of individual differences (Lerner, Bearer, Garcia, & Coll, 2004). A significant contributor to studies in behavioral genetics, provides this definition: “Behavioral genetics is the genetic study of behavior, which includes quantitative genetics (twin and adoption studies) as well as molecular genetics (DNA studies) of human and animal behavior broadly defined to include responses of the organism from responses measured in the brain such as functional neuro-imaging to self-report questionnaires” (Plomin, 2004).

Purpose of the study

The study of genetics has grown out of a desire to understand how exactly the individual comes to be just that, an individual different from its peers.

Significance of study

In order to comprehend the scope of possible outcomes and how they came to be behavioral genetics looks at a number of variables; these include the impact of our genes (nature), and our environment (nurture). A countless number of hypotheses were put to the test through research to analyze the degree of influence of each. In this paper, team A will discuss the methods of behavioral genetics, the various research techniques used, their testing populations and why used, along with proposed answers and explanations.

Literature Review

One of the first twin studies was conducted by Bouchard in 1979 when he found a set of monozygotic twins, babies from a fertilized egg that splits into two. The babies were separated at a few weeks old. The babies had many physiological and psychological similarities. Since Bouchard's initial study it has been proven that, while monozygotic twins raised together have many similarities, those separated at an early age have an even greater likeness. Since twins being raised together are more likely to highlight their differences in order to maintain some element of independence, behavioral geneticists argue that this indicates a strong genetic underpinning in human development (Plomin, 2004).

Research conducted by Grilo and Pogue-Geile (1991) correlated the familial relationships with extroversion. The study included monozygotic twins reared together and apart, dizygote twins reared together and apart, biological parents and children, biological siblings, adoptive parents and children and unrelated siblings reared together. The results reflected that the highest correlation was between monozygotic twins raised together and apart. The lowest correlation was between unrelated siblings raised together. For behavioral geneticists, these results conclude that genetics are at work in determining the extroversion of a person.

Behavioral geneticists suggest reasonable doubt in assuming connections between psychological environments and developmental results may be genetically ...