Hormones are chemical substances produced in the human body which regulate and control certain cells and organs’ activities. One hormone, testosterone, is an androgen that plays a major role in male sperm production, as well as affecting their behavioral reactions; aggression and selfishness are examples of high testosterone levels. Another hormone, cortisol, is a stress hormone, created in the adrenal glands that can impair verbal declarative memory, but also serve other functions such as regulating metabolism and controlling blood sugar levels. Both of these hormones’ functions are supported by the experiments conducted by Zak et al and Newcomer et al.
The study conducted by Zak et al was aimed to test testosterone’s role on male aggression; any behavior with the intention to harm. In order to do this, he gathered 25 male students and randomly allocated them into two groups: one group received a testosterone gel, and the other contained a placebo with no active ingredients. The experimental group was shown to have double the amount of testosterone compared to the placebo group. Both groups were asked to play the Ultimatum Game; each participant had the option to be generous or stingy with the money that they held control over. The other person had the option to accept or reject the offer; a rejection results in both people losing the money all together. The study was a double blind counterbalanced repeated measures design, meaning neither the participants nor the experimenter were aware of the condition, and the participants were only compared to themselves. The results show that 27% of the participants who were given the testosterone gel were stingier with the money versus the people who received the placebo, and the rejection rate of the offers was twice as high compared to those of the placebo group. The results of this study advocates that men who obtain high testosterone levels are expected to show more signs of selfishness and dominating behavior.
Zak et al’s (2009) study contains many strengths and limitations that may have impacted the results. After being debriefed, the participants displayed that they did not know what condition they were put under, eliminating demand characteristics. The experiment used the Ultimatum game as the medium for testing testosterone on male aggression, thus producing low ecological validity; the findings do not assess the function of testosterone in settings outside of the game. Instead of observing the aggression of the males, the study focuses on how testosterone affects their generosity, something that can be linked to aggression. Because 27% of the experimental group were less generous with the money they controlled, it shows that testosterone appears linked to generosity and selfishness, turning selflessness into selfishness. This also suggests that men with higher testosterone levels should be more likely to punish others for violations of norms throughout society, shown by the increased rejection rate of the game. Because of this, the findings provide insight on how testosterone provides an origin of violent and selfish behaviors encountered by men, examples being soldiers fighting in a war and reckless driving. Testosterone is a hormone naturally produced in the body, and therefore regulates men’s behaviors towards environmental situations.
The second study conducted by Newcomer et al (1999) , investigated if high levels of cortisol, a stress hormone, intervenes with verbal declarative memory. The sample of participants were pulled from Washington University Medical Center, who were all evaluated by a physician. All healthy participants were allocated by matched pairs by gender and age into three conditions: high levels of cortisol (160 mg, high stress), low levels of cortisol (40 mg, low stress), and a placebo group which contained no active ingredients. Each participant took one tablet every day for four days. In order to test their verbal declarative memory, they were asked to listen and recall parts of a prose paragraph over the four day period. The findings suggest that high cortisol levels impaired the performance of the memory task because the group displayed the only and the worst decrease in memory performance. The higher cortisol level group performed the task lower than the placebo group after day one, while the lower cortisol level group displayed no decrease in performance. This builds a relationship between the level of cortisol and memory.
The only ethical application observed throughout the study was the fact that cortisol impacted the participants’ memory in a negative fashion, though informed consent forms were signed before the study began, and the damage was not permanent; the effect only lasted while the participant was ingesting the tablet. Since Newcomer’s study was a controlled randomized experiment, a cause and effect inference can be made between levels of cortisol and the participant’s scores received from the verbal declarative memory assessment. The study in itself creates a causation between increased levels of the cortisol hormone and impairment of the participant’s declarative recall memory. The study’s findings imply that people who undergo high amounts of stress, or an increase of cortisol, will experience difficulty in the ability to recall information. This particular symptom is found in many diseases and disorders such as Alzheimer’s and depression. However, high amounts of the released hormone is not associated with the damage of the hippocampus, neurons, or any other parts of the brain, because the effects were reversible. With this being said, the cortisol hormone serves as a stress response which, in increased amounts, impairs memory.
The studies conducted by Zak et al (2009) and Newcomer et al (1999) both investigate how hormones affect the human body and its processes. Both hormones observed, testosterone and cortisol, affect human behavior in negative ways. The portrayal of testosterone in Zak et al’s study is a regulatory hormone which manages males reactions toward violations of social normalities. An increase of testosterone in the body influences the way they react to situations in a more selfish and irate manner. In Newcomer et al’s study on increased cortisol levels versus verbal declarative memory, a cause and effect relationship is created; as the hormone level increases, the ability to recall information decreases and develops a temporary memory impairment. In both studies, the researchers leave room to examine the hormones even deeper; an example being how cortisol affects a patient living with Alzheimer’s.