biological approach

• The biological approach assumes behaviour can be explained in terms of biological factors
• The body is made up of cells, with each cell consisting of 23 pairs of chromosomes.
• DNA is a chain of 2 or more nucleotides joined together. Chromosomes are made of DNA.
• Every cell in the body has exactly the same DNA
• DNA is divided into segments called genes. Each gene controls the production of one specific protein and genes control our physical traits.
• Animals of the same species broadly have the same set of genes whereas animals of different species have different sets of genes.
• Alleles are different versions of a particular gene. When a gene has different alleles, the trait has genetic variation
• Sex cells are either sperm cells or eggs. Each have 23 chromosomes. During reproduction, the sperm and egg combine to form a new cell with 23 pairs of chromosomes.
• Half of a persons chromosomes come from the mother, and the other half come from the father.
• Genetic inheritance is when traits are passed down from parent to child
• Genotype is a description of all of a persons genes and alleles
• Phenotype is a person's physical traits. It is controlled by genotype and environmental factors
• The biological approach studies the extent to which behaviours are determined by genetics
• Genes determine behaviour by affecting processes inside the brain
• It is unlikely that one gene is responsible for a behaviour, it is more likely caused by a combination of different genes. Environmental factors have a bigger impact on behaviour than they do for physical traits.
• Monozygotic twins come from one zygote which split into two identical zygotes. 100% of genes - same genotype, identical
• Dizygotic twins come from two different zygotes which were fertilised at the same time. 50% of genes, not identical
• A shared environment is the environment a pair of twins shares in common. A non-shared environment is the environment a pair of twins don't share in common. Monozygotic and dizygotic share some, but not all of their environment
• Twin studies assume MZ and DZ twins have a similar amount of shared environment and the impact of shared environment on phenotype is similar for both MZ and DZ
• Concordance is when two twins share the same phenotype. In twin studies, we don’t include sets of twins where neither twin has the trait we’re studying.
• Concordance rate is the percentage of twins who share a characteristic, given that at least one twin has the characteristic.
• Genetic variation contributes to a trait if the concordance rate for monozygotic twins is larger than the concordance rate for dizygotic twins.
• The bigger the difference in concordance rates between monozygotic and dizygotic twins, the more influence genetic variation has on the trait.
• The smaller the difference in concordance rates, the less influence genetic variation has on the trait.
• McGuffin 1996 studied the presence of depression in twins. MZ had concordance rates of 46%, DZ had concordance rates of 20%. Concluded major depression is likely to be partially influenced by genetics.
• A limitation of twin studies is MZ twins may share more environment than DZ twins because they tend to be treated more similarly. This means that the bigger concordance rate in MZ twins might be partly caused by a more similar environment not just genetics.
• evolution is when a species gradually changes, over many generations
• When a DNA mutation occurs, this creates a new, different version of the gene, meaning that a new gene allele is created.
• DNA mutations are small changes to alleles which can happen during reproduction.
• If a new allele makes an organism more likely to survive, the organism is more likely to pass on that allele to future generations
• Natural selection is when traits which increases chances for survival are passed onto future generations
• The process of natural selection means species will gradually adapt to their environment over many generations
• Natural selection means that species have alleles which make them more likely to survive and reproduce. A species' genotype is determined by natural selection
• The biological approach suggests natural selection shapes our behaviour because it causes us to have certain genes that control processes in the brain. Processes in the brain cause our behaviour
• Biological factors affect behaviour by influencing different processes in the brain
• Cognitive neuroscience combines the cognitive and biological approach to psychology. It is the study of which parts of the brain are involved in different mental processes
• fMRI & EEG's are used in cognitive neuroscience to detect activity in the brain
• Scientific. The biological approach is based on objective, empirical data. Experimental methods are controlled with standardised procedures to investigate cause and effect relationships in the body. This is beneficial as experiments can easily be replicated.
• Biological approach can be applied to understand and treat mental disorders. Understanding the effect of genetics on behaviour means that we can help people who are most likely to suffer from genetically inherited conditions. This is positive as the biological approach has has practical applications
• Overly reductionist. The biological approach reduces complex behaviour, thoughts and emotions to genetic or biochemical causes. This is problematic as it ignores social or cultural causes of behaviour