the biological approach

• genes the mechanisms of heredity: heredity is the passing of characteristics from 1 generation to next through the genes and is the reason why offspring 'take after' their parents in terms of psychological characteristics
• genes the mechanisms of heredity: genes carry the instructions for a particular characteristic (such as intelligence or temperament) but how this characteristic develops depends partly on the interaction of the gene with other genes, and partly on the influence of the environment
• genes the mechanisms of heredity: the extent to which a psychological characteristic is determined by genes or environment is called the nature-nurture debate
• genotype + phenotype: there is an important difference between the genotype - the genetic code that is 'written' in the DNA of a person's calls and the phenotype which is the physical appearance that results from this inherited information
• genotype + phenotype: whilst we might expect a direct relationship between the 2 this is not always the case e.g. in the case of eye colour, someone may inherit a recessive gene for blue eyes but this will not be expressed if they have also inherited a dominant gene for brown eyes from the other parent
• genotype + phenotype: in this case we can't determine the genotype (one for blue eyes gene, one brown eyes genes) from just observing the phenotype (i.e. brown eyes)
• the genetic basis of behaviour: each person possesses a unique combination of genetic instructions, therefore we differ from each other in terms of personality, intelligence, abilities etc
• the genetic basis of behaviour: the term heritability refers to the amount of variability in a trait within a population that can be attributed to genetic differences between people within that population
• the genetic basis of behaviour: the more that a trait is influenced by genetic factors, the greater the heritability e.g. studies of identical twins have suggested that the variation in individual intelligence what makes 1 person more intelligent than another could be 60-80% due to genes
• neurons and the nervous system: the nervous system is comprised of several connected systems = the central nervous system (CNS) comprises the brain and the spinal cord, then the peripheral nervous system (PNS) comprised of the somatic and autonomic nervous system
• neurons and the nervous system: the nervous system messages from 1 part of the body to another using individual nerve cells known as neurons
• neurons and the nervous system: neurons transmit nerve impulses in the form of electrical signals, many aspects of behaviour are under neuronal control including breathing, eating and sexual behaviour
• the brain: the largest part of the brain is the cerebrum - making up about 85% of the total mass of the brain
• the brain: the outer surface of the cerebrum is called the cerebral cortex which is responsible for many of the 'higher-order' functions such as thought and language
• the brain: the cerebrum is divided into 2 halves (known as hemispheres) with each hemisphere further divided into 4 different parts (known as lobes)
• neurotransmitters: when a nerve impulse reaches the end of 1 neuron, a chemical called a neurotransmitter is released
• neurotransmitters: it travels from 1 neuron to the next across a junction called a synapse
• neurotransmitters: there are different types of neurotransmitter, some of which trigger the receiving neuron to send an impulse and some stop it from doing so
• neurotransmitters: those neurotransmitters that trigger nerve impulses in the receiving neuron and stimulate the brain into action are called excitatory neurotransmitters
• neurotransmitters: those that inhibit nerve impulses in order to calm the brain and balance mood are called inhibitory neurotransmitters
• neurotransmitters: dopamine is an excitatory neurotransmitter that is associated w/ our 'drive' or motivation
• neurotransmitters: serotonin is an inhibitory transmitter e.g. Crockett et al (2008) found that when serotonin levels are low people tend to display increased aggression
• neurotransmitters: frontal lobes are involved w/ functions such as speech, though and learning
• neurotransmitters: temporal lobes are involved w/ hearing and memory
• neurotransmitters: parietal lobes process sensory information such as touch, temperature and pain
• neurotransmitters: occipital lobes process visual information
• hormones: hormones are chemicals that are produced by endocrine glands such as the pituitary gland which together make up the endocrine system
• hormones: in response to a signal from the brain, hormones are secreted directly into the bloodstream by the endocrine glands where they travel to their 'target cells' and exert their influence by stimulating receptors on the surface of or inside cells
• hormones: the presence of a hormone causes a physiological reaction in the cell, altering its activity e.g. Carre et al (2006) studied a Canadian ice hockey team over the course of a season
• hormones: they found evidence of a surge in levels of the hormone testosterone whenever the team played in their home stadium, suggesting the hormone energised the players to defend their home territory
• evolution + behaviour: Charles Darwin argued that over time organisms become adapted to their environment through biological evolution
• evolution + behaviour: this refers to the changes that take place in the characteristics of a population over time
• evolution + behaviour: the mechanism behind biological evolution is natural selection
• evolution + behaviour: people within a species differ from each other in terms of their physical characteristics and in their behaviour and at least some of this variation is inheritied
• evolution + behaviour: because people must compete w/ eachother for access to resources (mates, food et.) those who survive this competition and go on to reproduce will tend to have behaviours that are more likely to lead to survival and reproductive success than those who do not
• evolution + behaviour: these behaviours will be passed on to offspring and will become more widespread in the population, through the process of natural selection successive generations will develop behaviours that are even more likely to lead to survival and reproductive success
• evolution + behaviour: Buss (1989) studied 37 different cultures and found universal similarities in human mate preferences
• evolution + behaviour: women desired mates w/ resources (to provide for offspring) whilst men desired young, physically attractive women (an indication of their fertility and reproductive value)
• evaluation S: the biological approach has been tested using highly scientific methods such as brain scans and twin/family studies
• evaluation S: it has many practical applications such as the use of drugs to treat mental illness