Name: how behavior genetics studies inheritance
Uploaded: 2024-08-29T22:13:37.000Z
Duration: 1 min 23 s
Channel: JoVE

K12 Standards

Next Generation Science Standards

High School

Life Science

heredity-inheritance-and-variation-of-traits

Heredity: Inheritance and Variation of Traits

HS-LS4-3

Behavioral Genetics and Its Designs

Behavior genetics explores the role of inheritance in shaping human behavior.
Researchers use family, twin, and adoption studies to assess heritability by examining traits among relatives, helping to determine the role of genetics and environment in these traits.
In family studies, researchers track traits within biological families to identify genetic influences on behaviors such as depression or intelligence. This approach may reveal behavior patterns and potential genetic risks.
Twin studies involve comparing identical twins, who share 100% of their genes, with fraternal twins, who share about 50%. Identical twins typically show greater similarity than fraternal twins.
For example, twin studies show that identical twins have more similar IQ scores than fraternal twins.
Adoption studies investigate the effect of genetics and environment in shaping the behavior of children raised by adoptive parents.
For instance, if a child&#39;s biological mother is outspoken and cheerful, and the child has similar behavior despite being raised by introverted adoptive parents, it suggests that extrovert behavior is influenced by genetics.&#160;

behavioral genetics and its designs

Behavior genetics explores how genetic inheritance influences human behavior. It focuses on how genes, passed from parents to offspring, contribute to the development of behavioral traits and tendencies. This branch of genetics seeks to understand the complex interplay between inherited genetic factors and environmental influences in shaping our behaviors.
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique insights into the genetic and environmental components of behavior. In family studies, researchers observe patterns within biological families to identify genetic influences on behaviors. Such studies have been critical in identifying potential genetic risks for traits such as depression and intelligence. By tracking these traits across generations within families, scientists can uncover patterns that suggest a genetic basis for certain behaviors.
Twin studies compare identical twins, who share all of their genes, and compares them with fraternal twins, who share only about 50% of their genes. These studies are particularly valuable for examining the genetic contributions to traits like intelligence and personality. The key finding from twin studies is that identical twins tend to show more similarity in traits than fraternal twins, thereby highlighting the genetic foundations of these traits.
Adoption studies offer a unique perspective by examining children who have been separated from their biological parents and raised by adoptive parents. These studies focus on the resemblances between adopted children and their biological parents, rather than their adoptive parents, to assess the impact of genetic factors. Such studies have revealed that even when raised apart from their biological families, adopted children often display significant similarities to their biological parents in aspects like temperament and mental health. This resemblance is indicative of the strong role genetics play in the development of these traits.

Behavior genetics explores the role of inheritance in shaping human behavior.
Researchers use family, twin, and adoption studies to assess heritability by ...

Education

JoVE Core

Introduction to Psychology

Unit 1

Biopsychology

KEY TERMS AND CONCEPTS

how behavior genetics studies inheritance

Behavior genetics studies how inherited genes influence human behavior. It looks at how genes passed from parents to offspring help shape behavioral traits and tendencies. The field also examines how inherited factors and environmental influences work together.

Researchers use family studies, twin studies, and adoption studies to separate genetic and environmental effects. Family studies track traits within biological families to find possible genetic patterns. They have helped identify genetic risks linked to traits such as depression and intelligence.

Twin studies compare identical twins, who share all of their genes, with fraternal twins, who share about 50% of their genes. This comparison helps researchers study the genetic contribution to traits such as intelligence and personality. A common finding is that identical twins are more similar in these traits than fraternal twins.

Adoption studies add another important way to study behavior genetics. They follow children who were raised apart from their biological parents and compare them with their biological families, not their adoptive families. These studies show that adopted children can still resemble their biological parents in temperament and mental health, which supports the role of genetics in behavior.

How Behavior Genetics Studies Inheritance

how-behavior-genetics-studies-inheritance

introduction to biological bases of psychology

introduction-to-biological-bases-of-psychology

Biological Factors Shaping Behavior and Mind

Biopsychology connects biology and psychology by showing how the body influences behavior and mental processes. It focuses on the nervous system, neurotransmitters, hormones, genetics, and evolutionary ideas. Together, these areas help explain why people think, feel, and act the way they do. The nervous system is the main foundation of biopsychology. It has two parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain and spinal cord and...

nervous system

Nervous System: CNS, PNS, and Reflexes

The nervous system helps the body sense, move, and respond. It works through a network of nerve cells that carry signals around the body. This system has two main parts: the central nervous system and the peripheral nervous system. The central nervous system, or CNS, includes the brain and spinal cord. The brain acts as the body’s control center. It processes sensory information and helps coordinate responses. The spinal cord serves as a major pathway for signals between the brain and the rest...

neurons as communicators of the brain

Neuron Parts and Signal Transmission

Neurons are the cells that carry information through the brain and nervous system. They use electrical and chemical signals to help control body functions, from heartbeat regulation to complex thinking. Their structure is built for fast, efficient communication. The cell body, or soma, is the neuron’s control center. It contains the nucleus, which holds the cell’s genetic material and helps maintain the neuron’s health and function. The cytoplasm around it contains organelles that make...

neuronal communication

How Neurons Send Signals

Neurons send signals through electrochemical communication that supports brain and nervous system function. A key part of this process is the action potential, a rapid electrical change that starts when the neuron’s internal charge rises above a threshold. That signal then travels along the axon to the axon terminal, where it is ready to pass to another neuron. The connection point between two neurons is called a synapse. Synapses can be electrical or chemical, and each type moves information...

neurotransmitters

Brain Chemicals That Shape Mood and Movement

Neurotransmitters are chemical messengers that help neurons communicate. They play a major role in nervous system function, as well as in mood, movement, sleep, and social behavior. Serotonin is made in the brain and intestines. It is linked to well-being and happiness, and it helps regulate mood, appetite, and sleep. When serotonin levels are out of balance in the brain or in peripheral sites, depression and sleep problems can occur. Dopamine is produced in several brain areas, including the...

cerebral hemispheres

How the Brain’s Two Halves Work

The brain’s two cerebral hemispheres work together to process information and control the body. The left and right hemispheres are linked by the corpus callosum, a large bundle of nerve fibers. This connection lets the two sides share sensory and motor information, with each hemisphere controlling the opposite side of the body. The hemispheres are also specialized for different tasks. This is called lateralization, which means certain functions are handled more strongly by one side than the...

lobes of the cerebrum

How Brain Lobes Shape Perception

The cerebral cortex is divided into two hemispheres, and each hemisphere has four lobes: frontal, parietal, temporal, and occipital. Together, these lobes support the brain’s main cognitive and sensory jobs. They work as a team to help you think, feel, move, and respond to the world. The frontal lobe sits behind the forehead and acts as a control center for personality, intelligence, and voluntary muscle movement. It also contains the prefrontal cortex, a region that helps with planning,...

spinal cord

Spinal Cord Nerves and Reflexes

The spinal cord is a major part of the central nervous system. It runs from the base of the brainstem to the lumbar region of the vertebral column. It helps keep the body stable and carries signals between the brain and the rest of the body. The spinal cord sits inside the bony spine for protection. It is divided into 30 segments that match the vertebrae. Each segment connects to a specific body region through paired spinal nerves. These spinal nerves are grouped by where they leave the...

lateralization

Brain Hemisphere Specialization

Brain hemisphere specialization divides mental tasks between the left and right sides of the brain. This split can improve neural efficiency and support more complex human abilities. Each hemisphere tends to handle the work it does best, which helps cognitive processing run more smoothly. The left hemisphere is especially strong in logic and language-related tasks. It supports analytical thinking, which means breaking a problem into parts and solving it step by step. This is important for...

human genetics

Genes, Behavior, and Mental Health

Human genetics explains how genes can influence behavior, emotions, and mental health. It also shows how a person’s genetic code can shape physical traits and the risk of disease. Each individual carries a unique set of genes, so the effects can be subtle or more noticeable. Genes help direct how the brain, hormones, and cells work. These body systems are all shaped by genetic instructions, and they help produce differences in thoughts and behavior. Human genetics therefore links biology with...

genetic material

Chromosomes, DNA, and Inherited Traits

Chromosomes, DNA, and inherited traits explain how genetic information is organized in the human body. Each cell contains a nucleus, and the nucleus holds 46 chromosomes arranged in 23 pairs. These chromosomes are tightly coiled structures made of DNA, which carries the instructions passed from parents to offspring. An individual inherits one set of chromosomes from the mother through the egg and one set from the father through the sperm. This combination creates a unique genetic makeup. Of...

genetic variation

How Alleles Shape Inherited Traits

Genetic variation helps explain why individuals in the same species can look and act differently. It comes from differences in DNA sequences. This diversity matters because it helps a species survive and adapt when the environment changes. Variation starts at fertilization, when an egg and sperm cell join. Each of these cells carries 23 chromosomes, so the fertilized egg can have up to 46 chromosomes. Chromosomes are long DNA strands that contain genes, which are the basic units of heredity. <br...

Behavior genetics studies how inherited genes influence human behavior. It looks at how genes passed from parents to offspring help shape behavioral traits and tendencies. The field also examines how inherited factors and environmental influences work together. Researchers use family studies, twin studies, and adoption studies to separate genetic and environmental effects. Family studies track traits within biological families to find possible genetic patterns. They have helped identify...

evolutionary psychology

Evolutionary Psychology and Human Behavior

Evolutionary psychology explains human behavior and mental processes through natural selection. It uses Darwin’s idea that traits can spread when they help survival and reproduction. In this view, some common behaviors may be adaptations that were useful to our ancestors. One clear example is fear of snakes. This fear is nearly universal, which suggests that early humans who avoided snakes were more likely to survive deadly encounters. Over many generations, that caution could be passed on and...

organization of the brain

Brain Regions and Their Key Functions

The brain is the main control center of the nervous system. It processes sensory input, makes decisions, and directs body actions. Its structure is divided into the hindbrain, midbrain, and forebrain, and each part supports important functions. The hindbrain sits at the base of the brain. It helps regulate automatic life processes. The medulla oblongata controls involuntary functions such as heartbeat, breathing, and blood pressure. Nearby, the pons acts as a bridge between brain regions,...

neuroplasticity

How the Brain Rewires Itself

Neuroplasticity is the brain’s ability to change its structure and function in response to learning, experience, or injury. It allows neural circuits to reorganize over time. This flexibility supports lifelong development and adaptation. One part of this change begins when dendrites and axons grow. Dendrites receive signals, and axons send them. As they grow, the brain’s circuitry becomes more complex and can support more connections. Next, synaptogenesis occurs. Synaptogenesis is the...

brain imaging

Brain Scanning Techniques

Brain scanning techniques help scientists and doctors see the structure and activity of the human brain. These methods support the diagnosis, study, and treatment of neurological and psychiatric disorders. The main techniques include computerized axial tomography, or CT, positron-emission tomography, or PET, magnetic resonance imaging, or MRI, functional magnetic resonance imaging, or fMRI, and transcranial magnetic stimulation, or TMS. CT scans use X-ray technology to build detailed...

somatosensory, motor, and association cortex

somatosensory-motor-and-association-cortex

Brain Cortex Areas for Sensation and Movement

The brain cortex uses separate areas for sensation, movement, and higher thinking. The somatosensory cortex is in the parietal lobes. It helps the brain interpret touch, temperature, and proprioception, which is awareness of body position. The somatosensory cortex has an organized map of the body. Neurons at the top of this region mainly process signals from the lower body. Neurons at the bottom handle input from the upper body. This layout helps the brain locate sensory input with precision.

the endocrine system

Endocrine Glands and Hormone Signals

The endocrine system is a network of glands that send hormone signals through the body. Hormones are chemical messengers that help control many body functions. They enter the bloodstream and travel to cells with the right receptors, or target sites, so the signal can be received. Because of this, hormone effects are widespread, unlike the more localized effects of neurotransmitters. This signaling helps the body keep a stable internal environment, called homeostasis. Several major glands...

major hormones and their functions

Hormone Imbalances and Their Effects

Hormones are chemical messengers made by endocrine glands. They help control body functions and keep internal conditions stable. When hormone levels shift too far up or down, normal body processes can be disrupted. Several major hormones have clear roles in the body. Oxytocin is made in the hypothalamus and released by the pituitary gland. It supports social bonding, childbirth, and lactation. Low oxytocin can affect social interaction and stress response, and it may contribute to depression.

inheritance

Genes, Traits, and Mendel's Rules

Genes, traits, and Mendel's rules explain how characteristics pass from parents to offspring. Gregor Mendel's pea plant experiments changed how scientists understand heredity. His work showed that traits are controlled by discrete units inside organisms called genes. Genes usually come in pairs. One gene is inherited from each parent, and together they make a person's genotype. Genotype is the genetic blueprint for potential traits. Examples include blood type, eye color, and inherited...

gene-environment interactions

How Environment Shapes Gene Expression

Environmental factors can change how genes are expressed. Gene expression is a dynamic process, and traits can differ even in people with the same DNA. Radiation, temperature, behavior, nutrition, and stress all help shape the final outcome. The reaction range helps explain this process. It means genes set a possible range for a trait, while the environment helps decide where a person falls within that range. For example, genetics may allow a height range from 5'5" to 6'1", but nutrition,...

heritability

Heritability and the Environment

Heritability describes how genetic differences contribute to trait variation in a population. It is a statistical measure, so it shows how much of the spread in a trait can be linked to genes across a group. It does not tell you how “genetic” a trait is in an individual person. Heritability is usually expressed as a percentage. That percentage can change depending on which population is studied and what environmental conditions are present. This means heritability is context-dependent, not...

natural selection and adaptation

Adaptation in Changing Environments

Natural selection explains how organisms become better suited to their environments over time. It favors individuals with traits that improve survival and reproduction. Adaptation is the result. It includes genetic changes that help an organism function in specific conditions, such as extreme cold or thinner air at high altitudes. Adaptation is not only physical. Psychological adaptation also helps organisms, especially humans, succeed in their surroundings. These responses come from both...

natural selection and mating preferences

How Selection Shapes Mate Choice

Natural selection and mating preferences work together to shape how organisms survive and reproduce. Natural selection favors traits that help an organism fit its environment. Mating preferences are part of sexual selection, which influences who mates with whom and how genes are passed on. Evolutionary psychologists argue that these preferences are tied to instincts that support reproduction. For females, conception, pregnancy, and nursing create a strong need to choose mates who can offer...

criticisms of the evolutionary perspective

criticisms-of-the-evolutionary-perspective

Social Learning vs. Evolutionary Psychology

Social learning theory and evolutionary psychology offer two different ways to explain sexual behavior. A study in which strangers gave students compliments and then asked for casual sex showed a clear gender gap. None of the women said yes, while 70% of the men agreed. Evolutionary psychology explains this result by arguing that natural selection may have shaped women to be more selective about sexual partners. From this view, selectivity can help improve survival and reproductive success. It...

key terms and concepts

Explore how behavior genetics uses family, twin, and adoption studies to examine inherited influences on behavior, intelligence, personality, and mental health.

How Behavior Genetics Studies Inheritance | JoVE K12

JoVE Core Introduction to Psychology offers an engaging learning experience on the fundamental principles of psychology through concise video lessons. Students will explore important topics such as cognitive processes, emotional regulation, and neural mechanisms, establishing a strong foundation in the study of the mind and human behavior. This series provides an accessible and captivating approach to grasp the essential concepts of the discipline.

introduction to psychology

DNA as a Genetic Template

Structure of a Gene

A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the ...

DNA Packaging

Organization of Genes

Chromosome Structure

A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication.
The centromere is a DNA ...

The Nucleosome

DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside ...

Chromatin Packaging

Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 ...

Karyotyping

Position-effect Variegation

In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread ...

Histone Modification

The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational ...

Spreading of Chromatin Modifications

The histone&#160;proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are ...

Lampbrush Chromosomes

In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, R&#252;ckert observed LBCs in shark egg cells and coined the ...

Polytene Chromosomes

Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in ...

Histone Variants at the Centromere

Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as &#8220;mutant&#8221; forms that ...

Inheritance of Chromatin Structures

Epigenetics is the study of inherited changes in a cell&#39;s phenotype without changing the DNA sequences. It provides a form of memory for the ...

Euchromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions ...

Heterochromatin

chromatin-position-affects-gene-expression

Chromatin Position Affects Gene Expression

Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the ...

Genetics of Organisms

Mendelian Genetics
Evolution is caused by changes in the genetic composition of populations. In the field of population genetics, scientists model this ...

REF and WEF Fly Genetics
ExpandTo prepare for the experiment, be sure to obtain cultures of Drosophila melanogaster at least two weeks ahead of the ...

REF and WEF Fly Genetics
ExpandNOTE: At your station, you should have four vials of flies. They will be labeled as male or female. They will also be ...

Genetic Lingo

Overview

An organism is diploid if it inherits two variants, or alleles, of each gene, one from each parent. These two alleles constitute the genotype ...

Punnett Squares

Overview

A Punnett square displays the possible genotypes offspring can inherit from two parental genotypes. If a trait&#x2019;s inheritance pattern ...

Monohybrid Crosses

Overview

In the 1850s and 1860s, Gregor Mendel investigated inheritance by performing monohybrid crosses in pea plants. He crossed two plants that were ...

Dihybrid Crosses

Overview

To determine whether traits are inherited together or separately, Gregor Mendel crossed pea plants that differed in two traits. These parental ...

Trihybrid Crosses

Trihybrid Crosses
Some of Mendel&#8217;s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A ...

Law of Segregation

When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 ...

Law of Independent Assortment

While Mendel&#x2019;s Law of Segregation states that the two alleles for one gene are separated into different gametes, a different question of how ...

Test Cross

Alleles are different forms of the same gene. Humans and other diploid organisms inherit two alleles of every gene, one from each parent.

An allele is ...

Chi-square Analysis

The chi-square test is a statistical hypothesis test. It is used to check whether there is a significant difference between an expected value and an ...

Pedigree Analysis

Overview

A pedigree is a diagram displaying a family&#x2019;s history of a trait. Analyzing pedigrees can reveal (1) whether a trait is dominant or ...

Nature and Nurture

Many human characteristics, like height, are shaped by both nature&mdash;in other words, by our genes&mdash;and by nurture, or our environment. For ...

Probability Laws

Overview

The probability of inheriting a trait can be calculated using the sum and product rules. The sum rule is used to calculate the probability of ...

background-and-environment-affect-phenotype

Background and Environment Affect Phenotype

Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as ...

Multiple Allele Traits

The Concept of Multiple Allelism

Multiple allelism describes genes that exist in three or more allelic forms. Although diploid organisms, like humans, ...

X and Y Chromosomes

Among mammals, the gender of an organism is determined by the sex chromosomes. Humans have two sex chromosomes, X and Y. Every human diploid cell has 22 ...

Chromosomal Theory of Inheritance

In 1866, Gregor Mendel published the results of his pea plant breeding experiments, providing evidence for predictable patterns in the inheritance of ...

The Y Chromosome Determines Maleness

The Y chromosome is a sex chromosome&#160;found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human ...

Non-nuclear Inheritance

Most DNA resides in the nucleus of a cell. However, some organelles in the cell cytoplasm⁠&mdash;such as chloroplasts and mitochondria⁠&mdash;also ...

The Ratio of X Chromosome to Autosomes

In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined ...

Incomplete Dominance

Gregor Mendel&#39;s work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid ...

X-linked Traits

In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be ...

Lethal Alleles

Agouti: A Lethal Allele
Lucien Cu&#233;not discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is ...

Sex-linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological ...

Epistasis

In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence ...

X-Inactivation

The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, ...

Polygenic Traits

When more than one gene is responsible for a given phenotype, the trait is considered polygenic. Human height is a polygenic trait. Studies have uncovered ...

Dosage Compensation

In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one ...

Pleiotropy

Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause ...

Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. [Assessment Boundary: Assessment does not include the phases of meiosis or the biochemical mechanism of specific steps in the process.]

HS-LS3-1

How Behavior Genetics Studies Inheritance

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