Genetics and behavior Flashcards
How is genetic information structured and why is it important in psychology?
Genetic information is stored in chromosomes—23 pairs in each human cell, one of each pair from each parent. Chromosomes are tightly wound strands of DNA, which act as a blueprint for the structure and function of the body. The term genome refers to all the genes an individual possesses. Genes carry instructions to make proteins from amino acids, and since proteins are the building blocks of the brain and body, psychologists study genetics to understand its influence on behaviour. Advances in technology have greatly expanded research in this area.
What is gene regulation and how does it relate to epigenetics?
Gene regulation is the process by which cells control which genes are active (expressed) or inactive (silenced). This happens through mechanisms like methylation, where methyl groups block a gene from producing its protein, effectively switching it off. The gene can be reactivated through demethylation. This reversible regulation is studied in epigenetics. Although the gene itself is unchanged, its expression is manipulated. In early development, some gene silencing may become permanent if certain proteins are no longer needed—highlighting gene expression’s critical role in brain development.
What is genetic similarity?
this is referred to as relatedness. The greater the genetic similarities between two individuals or a group of individuals the higher the degree of relatedness
What is the significance of relatedness in twin and kinship studies in psychology?
Relatedness refers to the degree of genetic similarity between individuals, such as monozygotic (MZ) twins, dizygotic (DZ) twins, siblings, parents and children, or adopted children and adoptive parents. Because genes can’t be ethically manipulated in humans, twin and family studies are used to explore how genetic similarities relate to behavioural traits. These studies are correlational and help psychologists infer the influence of genes on behaviour by comparing individuals with varying degrees of genetic overlap.
How can twin studies be carried out?
- they can assess twins who have been reared together or they can study twins who have been separated and raised in different environments2
Limitations of twin studies
- investigators mistakenly compare reared-apart identical twins with raised-together identical twins, forgetting that both sets share several important similarities. (includes common age/sex/appearance/prenatal environment) therefore they are bound to have many similarities in behavior. Joseph (2002) points out that the better comparison group would be with pairs of unrelated people of the same generation.
It is difficult to disentangle environmental and genetic factors when testing twins who live together with their families.
What are Kinship (Family) studies?
they investigate genetic heritability of a behavior by looking at the incidence of a behavior over a number of generations and controlling for other variables, such as environment. usually, this is limited to 3 generations in most populations.
What is evolution?
Evolution is the process by which plants and animals developed by descent, with modification from earlier existing forms. These changes happen at the genetic level as organism’s genes change and coming in different ways through reproduction and are passed down generations
What is Darwin’s evolutionary theory?
is based on the principle of natural selection. This means that the variations possessed by members of the same species have different values when it comes to survival. Those variations are ‘adaptive’ will be the ones that allow those possessing them to survive -> being passed down generations.
What do evolutionary psychologists believe?
that if behavior exists in society today, then it must be a useful adaptation that has helped us survive and reproduce.
What is Seligman’s ‘preparedness’ theory?
He suggested that we are biologically ‘prepared’ to fear particular creatures for evolutionary reasons. Fears and phobias of animals are adaptive for humans because they promote the survival of the species in some way. In essence, humans are still influences by their evolutionary origins and hence are more biologically prepared to be fearful of certain things.
Limitations of evolutionary psychology
- been accused of biological reductionism, reducing everything to a genetic level + ignoring human free will and the complexity of human behavior (response = popularisation of their theory is criticised not the theory itself)
- The evolutionary approach can oversimplify complex behaviours. Additionally, there’s limited archaeological evidence about the daily lives of our ancestors, making it difficult to accurately connect modern behaviour to ancestral patterns.
- Finally, since we can’t directly trace genetic changes over evolutionary time, the methodology of the evolutionary approach faces significant challenges.
Why are rats and mice commonly used in research?
They share extremely similar DNA to us (97.5%). Similar in anatomy, physiology, and genetics
What are the advantages/disadvantages of invasive techniques over neuroimaging in brain research
While advanced neuroimaging has transformed brain research in humans and animals, it still lacks the precision of invasive techniques like surgical ablation (removal of brain tissue) and lesioning (destruction of tissue). These invasive methods allow researchers to study brain structures in much finer detail and with greater control, as they can target specific areas and sizes of tissue. This leads to more accurate and precise measurements of brain function compared to non-invasive imaging.
How do psychologists study the effects of hormones and pheromones on human behaviour?
Psychologists often use animal research to study hormones, as hormones function similarly in non-human mammals and humans. For example, researchers may inject mice with testosterone to observe changes in aggression or dominance. These experiments offer controlled environments that help isolate the effects of specific hormones. Notably, the hormone insulin—used to treat diabetes—was discovered through animal research. Testosterone has also been linked to a protective effect against depression, potentially explaining why major depressive disorder (MDD) is more common in women than in men.
What are the ethical considerations in animal research according to (APA)
- lab animals must be treated humanely
- euthanized if in unnecessary pain or distress
- not released into wild after experimentation
Any study should be justified with a clear scientific purpose
Limitations of animal research
- humans and animals are never exactly the same -> we can never know the extent of the difference
- humans and animals can differ psychologically, even if they are similar biologically
- animals may be stressed -> since they are tested in a strictly controlled environment
- similar does not mean identical
Value/strengths of animal research
- humans and animals are identical in many ways -> in terms of brain structure and genetically
- studies with animal models to produce results -> useful models of human behavior + life saving treatments can be developed
- animal studies allow researcher to embrace the full lifespan
- can be highly controlled
- animal subjects are relatively inexpensive, easy to handle and easily accessible
what is an animal model?
is a concept that refers to using animal research to test a certain cause-and-effect hypothesis about certain human behavior. ex, stress models, separation models, and medical models
