How does genetic influences behavior

However, while the genetic makeup of a child determines the age range for when he or she will begin walking, environmental influences determine how early or late within that range the event will actually occur.

Classical, or Mendelian, genetics examines how genes are passed from one generation to the next, as well as how the presence or absence of a gene can be determined via sexual reproduction. Gregor Mendel is known as the father of the field of genetics, and his work with plant hybridization specifically pea plants demonstrated that certain traits follow particular patterns. This is referred to as the law of Mendelian inheritance. Genes can be manipulated by selective breeding, which can have an enormous impact on behavior.

For example, some dogs are bred specifically to be obedient, like golden retrievers; others are bred to be protective, like German shepards. In another example, Seymour Benzer discovered he could breed certain fruit flies with others to create distinct behavioral characteristics and change their circadian rhythms.

Behavior can influence genetic expression in humans and animals by activating or deactivating genes. Behavior can have an impact on genetic makeup, even as early as the prenatal period. It is important to understand the implications of behavior on genetic makeup in order to reduce negative environmental and behavioral influences on genes.

EEG and PET scans have the ability to show psychologists how certain behaviors trigger reactions in the brain.

This has led to the discovery of specific genes, such as those that influence addictive behaviors. A variety of behaviors have been shown to influence gene expression, including—but not limited to—drug use, exposure to the elements, and dietary habits. Prenatal exposure to certain substances, particularly drugs and alcohol, has detrimental effects on a growing fetus. The most serious consequences of prenatal drug or alcohol exposure involve newborn addiction and fetal alcohol syndrome FAS.

Fetal alcohol syndrome affects both physical and mental development, damaging neurons within the brain and often leading to cognitive impairment and below-average weight. Exposure to drugs and alcohol can also influence the genes of children and adults. Addiction is thought to have a genetic component, which may or may not be caused by a genetic mutation resulting from drug or alcohol use. Temperature exposure can affect gene expression. For example, in Himalayan rabbits, the genetic expressions of fur, skin, and eyes are regulated by temperature.

Light exposure also influences genetic expression. Thomas Hunt Morgan performed an experiment in which he exposed some caterpillars to light and kept others in darkness. Those exposed to certain light frequencies had corresponding wing colors when they became butterflies for example, red produced vibrant wing color, whereas blue led to pale wings. Darkness resulted in the palest wing color, leading him to conclude that light exposure influenced the genes of the butterflies. Lack of proper nutrition in early childhood is yet another factor that can lead to the alteration of genetic makeup.

Human children who lack proper nutrition in the first three years of life tend to have more genetic problems later in life, such as health issues and problems with school performance.

Privacy Policy. Skip to main content. Biological Foundations of Psychology. Search for:. Genetics and Behavior. Learning Objectives Explain the role chromosomes play in carrying genetic information. All animals have some number of chromosomes, which transmit genetic material. Human beings have 46 chromosomes 23 pairs.

Humans have two types of chromosomes: autosomes and sex chromosomes. The purpose of this section is not to review papers linking epigenetics and behavior extensively, but to highlight the importance of learning environments not only for neural plasticity but also for the phenotypic manifestation of the genome, beyond the particular heritability of different learning processes and cognitive functions. The most recent genetic and epigenetic data we have available to us emphasize the crucial roles that education professionals, families and society may play when contributing to the education of people who can and want to make the most of their capabilities.

These influences can contribute to maximizing the skills that students have available to them to face a changing and uncertain world. Although brain formation and functioning are based on a genetic substrate that influences it to a moderate or high degree, the brain is also malleable and is affected by education and daily experiences, and therefore so too are cognitive functions.

As I have previously said, children are certainly no tabula rasa , but even a trait with high heritability might be greatly altered by the environment acting directly on brain malleability or through epigenetic modifications.

However, it has also to be pointed out that with the current data, it is still not possible to say with a sufficient level of confidence which traits can be improved more easily or which are difficult to change. Not every trait is amenable to meaningful change through educational interventions, and this depends on a variety of factors. Finally, current data also point to another significant factor in education: learning must be perceived as adaptive by the brain, as neural plasticity and epigenetic modifications are, and teaching style is crucial for this perception to occur.

The author confirms being the sole contributor of this work and has approved it for publication. The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The author thanks the language services facility of the Barcelona University for checking the written quality of the manuscript and for making it more concise.

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Rimfeld, K. Peer groups are unique in that, unlike families, peers can select each other based on mutual attraction. Research has demonstrated that adolescents, based on their own genetically influenced characteristics, initially seek out friends with whom they share similarities.

Moreover, due to socialization, peers grow to be more alike over the course of a continuing friendship. To date, there are only a few studies examining genetic and environmental influences on peer relationships, and most have focused on the similarities within the peer group rather than on the quality of the peer relationships.

For peer relationship quality, there are several dimensions of friendship moderately linked to genetic influences, including positivity validation, caring, warmth and support and, for girls in particular, behavioral and emotional problems. Certain negative aspects, such as conflict, betrayal, and criticism, are associated with the shared environment. Studies of group affiliations have suggested genetic influences on academic aspirations, delinquency, and popularity, although the methods used to draw these conclusions were somewhat problematic.

Future research using refined methods will help to clarify the influences on peers and friends. The basic influences on behavior, therefore, are genes, shared environment, and nonshared environment.

Although for any trait one may be more important than the others, all three influences are considered in behavioral genetic studies examining social behaviors.

To this end, researchers use various methods: mainly, family, twin, and adoption study designs. If a trait is largely influenced by genes, the correlation between MZ twins e.

Accordingly, unrelated children adopted into the same family do not correlate for genetic reasons. Shared and nonshared environmental influences can also be estimated using twin and family designs.

Because shared environmental influences are all environmental non-genetic factors that make family members similar to one another, such influences would be indicated by correlations that are similar across all family members living in the same household, independent of their genetic relatedness.

While this formula is necessary for estimating the relative effects of genes and environment, it becomes problematic in simple family designs studies in which there is no variation in the genetic relatedness of family members in the same household , whereby the two factors become indistinguishable since individuals that share many genes e.

Finally, nonshared environmental influences are, by definition, all environmental factors that make family members different, including measurement error. The best test of nonshared environmental influences is MZ twin correlations. Because MZ twins reared in the same family share all of their genes and shared environmental influences any correlation less than 1.

Adoption studies are ideal for identifying shared environmental influences. The most common design studies an adopted child reared by genetically unrelated adoptive parents. Any similarity between the child and the adoptive parents must be due to shared environmental factors.

Data on the biological parents makes it possible to further parse genetic and shared environmental influences by examining similarities between the adopted child and biological parents and similarities between the adopted child and adoptive parents.