Think of these influences as building blocks. While most people tend to have the same basic building blocks, these components can be put together in an infinite number of ways. Consider your own overall personality. How much of who you are today was shaped by your genetic inheritance, and how much is a result of your lifetime of experiences?
This question has puzzled philosophers, psychologists and educators for hundreds of years and is frequently referred to as the nature versus nurture debate. Are we the result of nature (our genetic background) or nurture (our environment)? Today, most researchers agree that child development involves a complex interaction of both nature and nurture. While some aspects of development may be strongly influenced by biology, environmental influences may also play a role. For example, the timing of when the onset of puberty occurs is largely the results of heredity, but environmental factors such as nutrition can also have an effect.
From the earliest moments of life, the interaction of heredity and the environment works to shape who children are and who they will become. While the genetic instructions a child inherits from his parents may set out a road map for development, the environment can impact how these directions are expressed, shaped or event silenced. The complex interaction of nature and nurture does not just occur at certain moments or at certain periods of time; it is persistent and lifelong.
In this article, we'll take a closer look at how biological influences help shape child development. We'll learn more about how our experiences interact with genetics and learn about some of the genetic disorders that can have an impact on child psychology and development.
Going From One Cell to Trillions
At its very beginning, the development of a child starts when the male reproductive cell, or sperm, penetrates the protective outer membrane of the female reproductive cell, or ovum. The sperm and ovum each contain chromosomes that act as a blueprint for human life. The genes contained in these chromosomes are made up of a chemical structure known as DNA (deoxyribonucleic acid) that contains the genetic code, or instructions, that make up all life. Except for the sperm and ova, all cells in the body contain 46 chromosomes. As you might guess, the sperm and ova each contains only contain 23 chromosomes. This ensures that when the two cells meet, the resulting new organism has the correct 46 chromosomes.
From Genotype to Phenotype
So how exactly do the genetic instructions passed down from both parents influence how a child develops and the traits they will have? In order to fully understand this, it is important to first distinguish between a child's genetic inheritance and the actual expression of those genes. A genotype refers to all of the genes that a person has inherited. The actual express of these traits is the person's phenotype. The phenotype can include physical traits, such as height and color or the eyes, as well as nonphysical traits such as shyness, a high strung temperament or a thirst for adventure.
Remember our building block metaphor from earlier? While our genotype may represent a blueprint for how children grow up, the way that these building blocks are put together determines how these genes will be expressed. Think of genes as something like a blueprint to a house. Two houses can be constructed from the exact same blueprint, but the materials chosen build each house can vary dramatically from one to the next.
Influences on Gene Expression
Whether or not a...