BLOA Outline principles that define the biological level of analysis. (8)

Principles of BLOA There are three underlying principles that define the BLOA 1.Biology correlates with behaviour: emotions and behaviours are products of the anatomy and physiology of the nervous and endocrine systems. 2.Animal research may inform our understanding of human behaviour. 3.Innate: patterns of behaviour can be inherited; behaviour is innate because it is genetically based (evolution)

Purpose of the Principles Main ideas for research on specific areas of behaviour and physiology. Helps to understand how behaviour can be caused or influenced by biological factors

Principles of BLOA 1) Behaviour is a result of biological/physiological factors 2) Bidirectional relationship between other levels of analysis Behaviour is not only a result of biological systems alone; cognition and environment may interact with biological systems and affect physiology Cognition can affect biology and biology can affect cognition 3) Nature vs. nurture debate (Interactionist Approach) Debate between whether human behaviour is attributed to biological or environmental factors Psychologists have an interactionist approach and take both into account 4) Reductionist approach Researchers break down complex human physiology and behaviour into its smallest components to study

Important Definitions Neuron: A nerve cell that transmits information through electrical and chemical signals Neurotransmitter: A signaling molecule in the synapses that transmits signals between neurons Hormone: A chemical secreted by an endocrine gland. Some biochemicals act as both as a hormone and neurotransmitter, for example adrenaline and serotonin

Neurons: Our Building Blocks Neurons are cells specialized to receive, process and transmit information to other cells. Bundles of neurons are called nerves. Blood vessels Sensory neurons Outer sheath Bundle of neurons Motor neuron Dendrite Axon

3 Main tasks of neurons 1.) Receive information from the neurons that feed it. 2.) Carry information down its length. 3.) Pass the information on to the next neuron.

Principle 1: Biological & Physiological Specific brain processes, neurotransmitters, and hormones can play a role in behaviour. These physiological processes are what forms the basis of the biological level of analysis, in relation to how it functions and therefore affects human behaviour in everyday life. For example, this relates to the idea of localization of function, in that each area of the brain is responsible for coordinating a certain part of our body/nervous system and thus our behaviour.

Kasamatsu & Hirai – Monk Serotonin Study (Serotonin) AimInvestigate how sensory deprivation affects the brain. Procedure Studied a group of Monks on a 72 hour pilgrimage to a mountain. The Monks were not allowed to speak, eat or drink. They were exposed to cold late autumn weather. After 48 hours, the Monks started seeing hallucinations of ancestors and feeling their presence. Findings Researchers took blood samples before and after their pilgrimage. The found increased level of serotonin in the Monks’ brain. Especially in the Hypothalamus and Frontal Cortex. Resulting in hallucination. Conclusion Sensory deprivation triggered the release of Serotonin. Serotonin – responsible for Sleep, Arousal level, and Emotions.

Adrian Raine (1997) A study which supports this principle was conducted by Adrian Raine (1997), in which he aimed to determine whether criminals pleading Not Guilty under Reason of Insanity (NGRI) had any biological defects, which explained their distinct behaviour. Raine showed that there was a difference in brain structure between normal subjects and NGRI’s. He found that: NGRIs had less activity in prefrontal cortex which is linked to self-control and emotion Subsequently showing how biological factors (brain structure) may thus affect behaviour

Adrian Raine (1997) This study supports the idea that there are biological correlates of behaviour because it was shown that there was a correlation between the behaviour of aggression and the physiology of the brain, in how when parts of the brain are damaged, the functions that are associated with it are impaired.

Connection to the Principle Raine showed that there was a difference in brain structure between normal subjects and prisoners that pleaded not guilty for reasons of insanity (NGRI) Subsequently showing how biological factors (brain structure) may thus affect behaviour This study supports the idea that there are biological correlates of behaviour because it was shown that there was a correlation between the behaviour of aggression and the physiology of the brain.

There has been criticism of reducing the explanations of behavior to the working of neurotransmitters alone is a reductionist approach. Psychologist acknowledge that neurotransmitters do play a role but do not rely solely on neurotransmitters to explain behavior. Principle 1: Biological & Physiological

Principle 2: Animal Research – Martinez & Kesner (1991) Aim: To see the role that acetylcholine has on memory formation. Method: Experimental study using rats. They were trained to run a maze. They were divided into three groups. Group 1: received injection with scopolamine (blocks Ach receptor sites, reducing available ACh). Group 2: received injection with physostigmine (blocks production of cholinesterase (enzyme) which cleans up Ach from the synapses) leading to more available ACh. Group 3: The control group.

Procedure: 1. All rats were placed in the maze individually and completed the maze (maze had reward of food at the end) 2. Rats were given their respective treatments (see 3 groups above) 3. Rats were placed in maze individually and time taken to complete maze was measured Results: Condition 1 (rats that were injected with scopolamine) took the longest to complete the maze Condition 2 (rats that were injected with physostigmine) took the shorted amount of time to complete the maze Condition 3 (rats with no treatment) had maze-completion times between the condition 1 and condition 2 rats Principle 2: Animal Research – Martinez & Kesner (1991)

Connection to the Principle The study shows that ACh is important in memory since the rats showed different memory capacity depending on ACh level. Possiblity that humans can be treated with acetylcholine or physostigmine for memory-loss Since this was a controlled laboratory experiment, it can be concluded that the level of ACh is one factor that affects memory but the neurobiology of memory is very complex.

Principle 3: Evolutionary (Innate) Darwin’s Theory of Evolution 1. Heredity: Offspring inherits the traits of their parents 2. Natural selection: -Competition of resources must inevitably arise between organisms. -Traits which enhance adaptation and thereby survival and reproduction rates, are the most likely to be transmitted over generations. -Suggests that behaviour develops over time genetically

3. Speciation: Development of different species occurs because the more adaptive species in an environment overcomes competitors. 4. Variation: Even if more adaptive traits are most common, there is a variation of traits in a population of a species. This enables the species to adapt to sudden environmental changes. Principle 3: Evolutionary (Innate) Darwin’s Theory of Evolution

Principle 2: Evolutionary/Innate Survival of the fittest (Organism’s Fitness) An organism’s ability to survive depends on how well its characteristics allow it to: Exploit the opportunities available in its environment Avoid or deal with the threats presented by its environment The selection of traits which are beneficial to survival and reproduction. Selfish gene – we are all inherently “selfish” because we have an innate need to increase the chance that our genes be propagated.

Aim- Prove that nurture determined gender identity, not nature. Procedure Original name: Bruce Reimer Longitudinal study on Bruce/Brenda/David Reimer. Freak accident, the penis of one of the Reimer twins (Bruce) was so badly burned that it literally fell off after several days. Money suggested that the parents give him a sex change and changed Bruce’s name to Brenda Money did not reveal his true motive was to prove that nurture determines gender identity, not nature. Principle 2: Evolutionary/Innate Money- David Reimer Sex Change Case Study

Findings Although his name was Brenda and he was reared as a girl, he displayed masculine behaviour. There was nothing feminine about Brenda. By age 2 she was angrily tearing off her dresses. She refused to play with her dolls, and would repeatedly steal her brother’s toy cars and guns, beating him up for good measure. She acted like a boy in the way she spoke, sat, moved, and played. As Brenda’s teachers reported, she simply seemed to be a boy “by nature.” When she turned 10, Brenda began to exhibit sexual attraction to girls, and at age 11 the pubertal changes associated with being a boy kicked in—including increased muscle mass in the upper torso and lowered vocal frequency. She was ridiculed at school and given the name “Cavewoman.” Principle 2: Evolutionary/Innate

Findings Her school life deteriorated Compelled to undergo hormonal therapy by Money and her parents, she started to develop breasts and fat deposits around her hips as a result of the injections—but she used overeating and weight gain as a strategy to try to hide this feminization of her figure. Brenda dropped out of school, and her mother was admitted to a psychiatric ward to prevent suicidal behavior. Her father was drinking heavily. Brenda’s psychiatrist decided it was time for Brenda’s parents to tell her the truth. Brenda Reimer changed her name to David, began life as a boy, and after a seemingly endless series of painful surgeries successfully grew into a fairly handsome man who ultimately married and raised a step-family for many years—until his life took a downward turn, and he committed suicide in May of Principle 2: Evolutionary/Innate

Conclusion Proves the psychosexual development is determined by chromosomes and hormones. Ethics Ethical guidelines: Unethical A lot of deception and uninformed consent. No protection from physical and mental harm. No rights of withdrawal. Further research--- Milton Diamond was not convinced, he examined the role of hormones on the developing fetus. Suggesting that psychosexual development is not determined by genitalia or upbringing, but rather chromosomes and hormones.

Conclusion Sufficient support for the principles of the BLOA. All three principles, along with other factors need to be taken into account before determining these principles as the sole influences of human behaviour. These principles help to guide studies from a biological perspective. Views from all levels of analysis need to be taken into account before reaching a determined decision on influences on human behaviour.