The 3 Differences Between Shared Environment And Non-shared Environment

Since it was founded, Psychology has been a science that has tried to explain human behavior.

Since its founding, Psychology has been the science that has tried to find explanations why people behave in such different ways.

After decades of research and heated discussions about whether genetics or environment are more influential in shaping a person’s personality and behavior the now more than famous ‘nature vs nurture’ debate has been overcome, giving both factors more or less the same prominence.

Some of the causes that make us look more like our parents than the neighbor are found in our genes, but, at the same time, the neighborhood in which we live or the region where we live also influence our behavior.

Once the debate was over, we tried to understand something that happens in all families. Although the brothers look quite similar, there is always something that differentiates them. Their genotype, although not exactly the same, cannot be. Nor should the environment be, because all family members receive the same influences from it, right?

In psychology and behavioral studies, the terms shared environment and non-shared environment refer to two key factors influencing human behavior, personality, and development. These concepts help explain how individuals, even within the same family, can grow up to have different traits, habits, and behaviors. In this article, we’ll explore the three main differences between shared and non-shared environments.

Differences between shared environment and non-shared environment: a summary

Although tragic, the study of behavior, intelligence and personality in identical twins separated shortly after birth has been one of the most beneficial situations to understand to what extent certain phenotypic traits are heritable and which depend on the environment in which one is raised. The premise is that if two monozygotic twins, that is, two genetically speaking clones, live in different houses, those aspects they share will be due to their genetics, while those in which they differ will be due to the environment and/or their interaction with the genotype. of these people.

Thomas Bouchard is an American psychologist and geneticist who has studied pairs of twins separated at birth. In their project, the Minnesota Study of Twins Reared Apart investigated how genetics and environment influence the personality of twins reared apart. In this type of studies, genetics is given a lot of importance, but it can be seen that the environment influences how people behave.

The environment is understood as the set of aspects external to the person that may or may not exert some type of influence on personality, cognitive ability and behavior of the individual. Bouchard-style studies assume that growing up in different homes implies different environments, while growing up in the same home tends to mean growing up in the same environment.

However, for some time now and even raised in Bouchard’s own study, the possibility has been raised that living in the same home and, therefore, growing up with the rest of the biological siblings, does not have to mean that the same environmental influences. The reason for this is the obvious fact that siblings are not equal in terms of behavior or abilities.

It is true that siblings from the same family have not inherited the same genes, each and every one of them, otherwise we would not be talking about siblings, but rather identical twin brothers. However, the genetic basis is there, and that should imply that there are very few differences between siblings, which is rarely the case.

Even between monozygotic twin brothers raised in the same home there are differences. The differences must necessarily be explained by the environment, but having grown up in the same home, how is it possible that behavioral differences also occur?

This is when we talk about the shared environment and the non-shared environment, two factors within the concept of environment or environmental influences that allow us to understand the differences and similarities of the members of the same family. Let’s address in more depth what these two concepts mean.

1. Definition: Common Experiences vs. Unique Experiences

Shared Environment: Common Family Experiences

A shared environment refers to the environmental factors and experiences that are common to siblings raised in the same family. This includes shared parenting styles, socioeconomic status, cultural upbringing, and family traditions. These shared experiences often contribute to similarities between siblings.

Example: Growing up in the same household, attending the same family vacations, or having similar rules enforced by parents.

Non-shared Environment: Individual Experiences

In contrast, a non-shared environment includes the unique experiences and influences that are specific to an individual, even if they grow up in the same household. These factors contribute to the differences between siblings, such as distinct friendships, different teachers, or unique life events.

Example: One sibling may excel in sports due to an influential coach, while another sibling may develop artistic talents through a unique art mentor.

2. Impact on Personality Development: Similarities vs. Differences

Shared Environment: Creates Similarities

The shared environment typically contributes to similarities among siblings. It helps shape common family values, behavioral patterns, and cultural norms that siblings may adopt collectively.

Example: Siblings raised in a household that values academic achievement may both develop strong work ethics.

Non-shared Environment: Creates Differences

Non-shared environments, on the other hand, are responsible for the unique personality traits and behaviors of each individual. These experiences often explain why siblings can have contrasting temperaments or interests despite growing up together.

Example: One sibling might become outgoing and confident due to their unique social circle, while another remains introverted due to different peer influences.

3. Sources of Influence: Family vs. External Factors

Shared Environment: Family-Based Influences

Shared environmental factors are primarily derived from family-based settings and interactions. This includes parenting practices, household rules, and family values. These factors are consistent across all children in the household.

Example: Parents enforcing a strict study routine for all children in the home.

Non-shared Environment: Individual External Influences

Non-shared environmental factors are often external and unique to the individual. They can include life-changing events, individual friendships, unique opportunities, or personal challenges.

Example: One sibling may experience bullying at school, while the other forms strong friendships, leading to different emotional outcomes.

Beyond biology and genes

Both shared and non-shared environments, in addition to genetics, are behind how people are. Although, it should be noted that the research indicates that The influence of the two types of environments is different depending on the evolutionary stage. During childhood, the shared or family environment takes on a fundamental role, being something that strongly shapes the person. With the passage of time, the influence of the family environment collapses, and the non-shared or individual environment becomes more important.

In fact, as an example of this, a very general view among adults when asked what they believe has the most influence on a person’s way of being is that Genetic inheritance, along with one’s own experiences (often leaving aside how one was raised) are factors that must be taken into account that explain the behavior of each one.

Obviously, this does not mean that extremely harmful childhood situations, such as situations of abandonment and abuse, do not influence how a person may end up being as an adult. However, leaving aside extreme cases, greater importance is usually given to heritability along with the individual stimuli that have been received throughout life.

The key differences between shared and non-shared environments lie in their definitions, impacts, and sources of influence. Shared environments foster similarities among individuals through common family experiences, while non-shared environments create differences through unique external influences and personal experiences. Understanding these distinctions helps explain the diversity in personalities, preferences, and behaviors, even among individuals raised in the same family setting.