Genetics and Genetic Similarity

Behavioral Genetics

Study of how genetics and environment both contribute to individual variations in human behavior (with a key idea being that genes do not cause behavior, but may create predispositions toward certain behaviors)

genetic inheritance

The process of transmitting genes from the parents to their offspring; 23 chromosomes come from an individual's mother and another 23 come from their father

G x E

Stands for “gene-environment interaction”

gene-environment interaction

The phenomenon where an individual's genetic makeup influences their responsiveness to environmental factors. This means that the effects of environmental exposures on traits, diseases or disorders can vary significantly depending on an individual's genetic predisposition.

traits

Characteristics that are inherited, from parent to offspring

Epigenetics

The study of how environmental influences (factors beyond genes) alter gene expression (and their behavioral effects) without actually changing the DNA of the gene

gene expression

A complex chemical reaction to environmental or physiological changes that allow a gene to be activated and affect behavior

genes

Portions of DNA sequences that direct protein synthesis and produce cell structures (this is one aspect of how we get behavior, but these cannot affect behavior UNLESS they are expressed)

Diathesis-stress model

Suggests that a person may be genetically predisposed for a psychological disorder (or, more broadly, a behavior) that remains unexpressed until triggered by stressors from the environment

allele

One of a number of different forms of a gene

genotype

An organism's genetic makeup, or allele combinations

5-HTT serotonin transporter gene

This gene plays a significant role in regulating serotonin levels in the brain, impacting mood, anxiety, and overall emotional well-being. Variations in the gene, particularly the presence of short (s) and long (l) alleles, have been associated with different sensitivities to stress and a predisposition to mood disorders such as depression and anxiety.

kinship studies

Researchers assess genetic hereditary influence by examining blood relatives to see how much they resemble each other on a specific trait

genetic similarity

The measure of the proportion of alleles shared by two populations; research psychologists use twin studies, family studies (kinship studies), and adoption studies to help determine this

correlation

Statistical relationship between two variables; scientists use this approach with genetics because it is unethical to alter genes in humans in order to study the effects