Explain, using examples, functions of two hormones in human behavior

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The biological level of analysis studies human beings as biological systems, meaning that many behaviors are attributed to physiological origins. Thus, our cognitions and emotions are believed to be products of the anatomy and physiology of the nervous and endocrine systems. This is not to say that behavior is the result of biological factors alone, but that we should also consider the bidirectional relationship between cognition and biology. A great deal of research at this level of analysis has focused on the role of hormones in human behavior. Hormones are chemical messengers that are secreted by the glands of the endocrine system and can have a widespread effect on both physiology and psychology. This essay will explain the functions of oxytocin and adrenaline.

Oxytocin is often referred to as the “love hormone” or “trust hormone”, which stems from the fact that it is released when one hugs, kisses and touches. The hormone is produced by the hypothalamus, after being stimulated by the pituitary gland.

A notable research study was conducted by Morhenn et. al (2008), who randomly assigned 96 students to a massage-and-trust, rest-and-trust or massage-only group. The massage conditions consisted of 15-minute Swedish massages (a light massage which was shown to increase oxytocin levels in many people by Turner et al., 1999), while the rest condition required participants to rest for the same amount of time in the same room. Then, participants in the first two conditions mentioned played a trust game that required them to make a decision about how much money they would give to another participant, knowing that this money would be tripled and that the other participant might share the profit. Sending a large amount of money was taken to indicate a high level of trust. Blood samples were taken twice, once at the beginning of their participation and once again close to their decision in the trust game, so that oxytocin levels could be measured.

The group that received only the massage were tested immediately after following it. There was no significant change in their levels of oxytocin overall. Participants in the massage-and-trust group who made the decision about sending money to another participant sent 6.30$ on average, only slightly more than the group who had simply rested without massage. In addition, a positive correlation was found in participants who were sent money and the change in their oxytocin level, according to whether they had received a massage or simply rested. 

The researchers concluded that while one episode of touch in the form of massage was not enough to raise oxytocin levels, the act seemed to prime participants to sacrifice money when a stranger displayed trust towards them by sending them an amount of money. In this sense, oxytocin levels are able to predict the amount of sacrifice the participants made in the trust game, suggesting that oxytocin’s effect on behavior is to increase generosity and cooperation among adults. 

Although the use of the experimental method with 3 distinct conditions increases the study’s internal validity, further research or relevant findings may be needed to validate the results. This is because concepts like trust are not easy to operationalize and the link between a hormone and social behaviors may not be accurate. As the study involved only students, there is sampling bias which may be said to limit generalizations to different populations. Furthermore, the setting was somewhat artificial, as it is likely that it led to demand characteristics. The correlations were suitable for the purpose of the study and did indicate one, but it does not necessarily establish a causation too.

Another hormone that has a number of effects on the human body is adrenaline, secreted by the adrenal medulla of the adrenal gland. A general description of its effects is the “fight or flight” response. Adrenaline prepares the body for action to help the organism deal with a threat, either by fighting it or by running away from it. The hormone increases the flow of oxygen and blood to the brain by increasing the heart rate and dilating blood vessels. Key resources like oxygen and glucose are transferred away from internal organs towards the extremities of the body (muscles), as functions like digestion are less important in a stressful situation. Although we associate adrenaline mostly with negative emotions, such as fear, those who take part in extreme sports know that exposing themselves to danger is thrilling and the release of adrenaline in such cases is associated with positive feelings. Various studies have attempted to investigate its role in the creation of emotion. 

To test this hypothesis, they recruited volunteers to receive a vitamin injection and informed them that they would be participating in vision experiments. None of the 184 male participants received the injection they believed they were getting, as 3 groups received an adrenaline injection and a 4th group received a placebo injection of saline solution. The 3 groups receiving adrenaline were given different types of information about possible side-effects. One group was told that they might experience an increased heart rate and shaky hands (the actual effects of an adrenaline injection). The second group did not receive any information and the third group was told that some people experienced a headache and numbness or itchiness in the feet. Thus, the first adrenaline group understood how their body would react and had an explanation of its cause, while the other two groups would inevitably experience the same physiological changes but without explanation. 

To manipulate the nature of emotion, Schachter and Singer constructed two contexts: euphoria, in which a confederate encouraged the participant to join games with office equipment in a waiting room, and anger: in which a confederate filled out a mock questionnaire at the same pace as the participant, but getting increasingly outraged by the increasingly personal nature of the questions. The researchers used observational data based on structured observation in each condition and then asked them to complete a self-report form that assessed their mood in terms of anger and happiness when they were finished. In the euphoria condition, it was clear that the groups who had received an adrenaline injection without the correct information showed more of the euphoric behaviors and also reported more happiness. Although the anger context did not elicit the corresponding pattern of reporting, the researchers suggested that this might have resulted from discomfort in reporting anger compared to happiness. They relied instead on behavioral data, which did show that participants who were aware of the real expected physiological changes performed less of the angry behaviors than the groups who had no explanation. 

It was concluded that emotion occurs by a process of cognitive labelling -that is, the interpretation of physiological cues is combined with contextual cues to construct a person’s subjective feeling of an emotion. The use of a structured observation and different conditions increased internal validity, but one possible limitation is that no assessment of the participants’ mood was made prior to the study. Also, the sample consisted only of males so caution should be used when generalizing to other populations. The study involved important ethical considerations, as those in the group who had not received information about side effects, were exposed to an anxiety-provoking situation. Researchers should ensure that participants leave the study in the same mental state as before and that physical discomfort is minimized. Also, deception was employed as it was necessary to test the assumptions, but in such cases it is particularly important to fully debrief participants at the end of the study and clarify any aspects that confused them. 

To conclude, according to the research mentioned above hormones have a very direct effect on physiology but their role in emotion and cognition can be complex, involving more than one factors. 

Ioannis P. IB Psychology tutor

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