Using one or more examples, explain functions of two hormones in human behaviour
Hormone 1 - Glucocorticoids
Glucocorticoids are stress hormones. All vertebrates
respond to stressful situations by releasing hormones, such as adrenalin and
glucocorticoids, which instantaneously increase the animal's heart rate and
energy level. This provides more energy to our muscles, increases blood pressure and turns off
everything that's not essential to surviving, such as digestion, growth and
reproduction. These are physiological responses to stress. There are also psychological responses to these hormones. In the short term, we think more clearly and aspects of learning and memory are enhanced, but over long periods of time, these effects can be reversed, as some of the evidence below indicates
Sapolsky. R, (1996) - Why stress is bad for the brain
Aim: To describe the impact of the stress hormone cortisol and other similar compounds (collectively known as glucocorticoids) on the hippocampus – a part of the brain involved in learning and memory.
Research method used: Review article describing data from correlation studies using MRI scanning in humans and in vitro lab studies of hippocampal cells. Procedure: MRI scanning - Sapolsky used MRI scanning to examine the brains structure of humans and compared the size of the hippocampus with the self reported levels of stress or depression that the patients suffered. In vitro studies - In in vitro studies, experiments are done to live cells which have been removed from the body of the animal and are being grown in a lab. This allows their reactions to certain chemicals to be studied much more closely than in a body. Findings: MRI scanning - Sapolsky found that those who experienced ongoing chronic stress or depression (which elevated glucocorticoid levels), had smaller hippocampi than those without stress or depression. In vitro studies - In in vitro studies, dripping glucocorticoids on hippocampal cells made them shrink. Conclusions - Chronic stress may result in prolonged glucocorticoid excretion leading to physiological changes such as damage to the immune system and impairment of learning and memory as high amounts of glucocorticoids result in atrophy of the hippocampus. Evaluation:
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I love Robert Sapolsky! He's a great lecturer, an interesting scientist and an entertainingly eccentric presenter! He's on top form in this excellent documentary about stress
Don't forget the question title... it's about BEHAVIOUR!!It is very easy to talk about this study and only mention the physical effects of stress hormones... BUT THAT WOULDN'T ANSWER THE QUESTION! You must make it clear that you are relating the physical effects to behavioural consequences.
Assignment 1 - Triangulating evidence: Marmot's Whitehall studiesMarmot's studies (e.g. Marmot et al, 1991 - the Whitehall II study) are introduced in the documentary above, so you should be familiar with their general approach and the evidence they found already.
To further your understanding, read this document and listen to this radio show about the experiments. Fill in a research study box fill (below) summarising the study. Make sure you include explanation of how this links to Sapolsky's evidence. What conclusions can you draw from the results of both studies together?
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Hormone 2 - Adrenalin (epinephrine)
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Adrenaline (or epinephrine if you are American) is perhaps the hormone that we are all most familiar with, both in name and in feeling its effects. It is a natural stimulant made in the adrenal gland of the kidney (as stated in the introduction). It is also a stress hormone (like glucocorticoids), released in response to anxiety, exercise, or fear. It affects bodily functions such as the heart rate, dilation of the pupils, and secretion of sweat and saliva. These functions are the ones often summarised as being part of the 'fight or flight' response.
When an animal is threatened, the options are usually either to stand its ground and fight, or run away as fast as possible. Both responses would require extra supplies of blood and oxygen in the muscles. Fright causes the brain to send signals to the renal glands which start pumping large amounts of adrenalin into the bloodstream. This increases the heart and breathing rate in preparation for the ensuing action. |
Cognitive, social, and physiological determinants of emotional state - Schachter, S., Singer, J.-E. (1962)
Schachter and Singer (1962) developed the two-factor theory of emotion. The two-factor theory suggests that emotion comes from a combination of a state of arousal and a cognition that makes best sense of the situation the person is in.
For example, the two-factor theory of emotion argues that when people become aroused they look for cues as to why they feel the way they do. Their study has its own page here on the AS section of the site, so go there first to read about the research |
Assignment 2 - 8 mark question
After you've read all the material on this page and made notes, try to write a full page of A4 in answer to the following question:
Using one or more examples, explain functions of two hormones in human behaviour (8)
Remember to always answer the question carefully, addressing the command term and also always bringing your evidence back to HUMAN BEHAVIOUR! Submit your essay by email or through the form on the home page.
Using one or more examples, explain functions of two hormones in human behaviour (8)
Remember to always answer the question carefully, addressing the command term and also always bringing your evidence back to HUMAN BEHAVIOUR! Submit your essay by email or through the form on the home page.
Triangulation and critical thinking alert!!
The ThinkIB site gives two sample student answers to the question "Using at least one study, discuss how environmental factors affect physiological processes. (22)" You might ask how this is relevant to the hormones section... but think about it. In all of the cases above, we clearly see how the environment and biology can interact to produce behaviour. You could therefore use these studies to answer more than one question if you are thoughtful enough!
This is exactly what we see in the ThinkIB samples - they use studies of hormones to answer a question on the environment and physiology. Two issues for the price of one!
N.B. It is important to remember that being able to use a study in more than one place doesn't mean you can ignore other relevant evidence (you still should learn the studies on the 'Environment on Physiology' page, for example). It does, however, mean that you will be able to write an essay with more more evidence and therefore much greater depth of analysis.
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