Using one or more examples, explain functions of two hormones in human behaviour.
- State what you are doing in the essay
- This essay will attempt to give a detailed account including reasons or causes of functions of hormones in human behaviour.
- Define hormones
- Hormones can affect human behaviour.
- Hormones are chemicals released by glands in the endocrine system which circulate in the bloodstream and act as messengers affecting particular cells and organs.
- Define endocrine system
- The endocrine system is a system comprised of glands, which secrete hormones into the bloodstream to affect behaviour.
- From there, the hormones are sent to target cells by impulses which initiate specific responses.
- Give examples of hormones
- The human body contains various hormones which relate to specific emotions and carry out different responses and actions in the body.
- Some hormones produced by the body are adrenaline and cortisol from the adrenals; melatonin, from the pineal gland; oxytocin from the pituitary gland and hypothalamus and testosterone and oestrogen from the gonads (testes/ovaries).
- Outline hormones
- Hormones have widespread effects on both physiology and psychology in humans and thus behaviour.
- Hormones enter directly into the bloodstream so thus they take longer to produce changes in behaviour that neurotransmitters
- State which two hormones will be explained in the following essay
- The two hormones which will be explained in the following essay and supported by psychological research are adrenaline and testosterone.
Hormone 1: Adrenaline
- Outline adrenaline
- The first hormone which will be explained is adrenaline.
- Secreted in the Adrenal glands, located above both kidneys.
- Explain the functions of adrenaline
- This hormone is known for the "flight or fight" reaction and arousal.
- Thus adrenaline is a hormone that helps an organism deal with an external threat (in the environment) in preparing the body to fight it or run away.
- Adrenaline can increase flow of oxygen and blood to the brain (increasing activity in the heart and dilating blood vessels).
- Some symptoms which adrenaline causes the body to do are:
- Increase in heart rate and blood pressure.
- Dilation of pupils in eyes.
- Transfers key resources (such as oxygen and glucose) away from internal organs to the extremities of the body
- Functions like digestion are less important thus slowed down being focused in helping an organism fight or run away from danger
- Increases alertness
- It has been suggested that adrenaline may be responsible for the creation of emotion
Study 1: Schacter and Singer (1962)
Introduce Study - Signpost
- A study looking into the effects of adrenaline on humans was conducted by Schacter and Singer (1962)
- To test the two factor theory of emotion (that emotion arises from a combination of a cognition and arousal), using the hormone, adrenaline.
- Test 184 college males
- Divided into 4 groups
- All groups were told that they were going to be given an injection of Suproxin in order to test its effect on vision
- Even though men were really receiving adrenaline
- First three groups were given an injection of adrenaline
- Last group was given a placebo
- 4 Groups divided into 2 subgroups
- Condition 1 - euphoria
- Confederate encouraged participant to play with games inside the waiting room (with office equipment)
- Condition 2 - anger
- Confederate completed a questionnaire at the same pace as the participant but became more and more angry as the questions became more personal
- Participants were either informed of the correct effects of adrenaline (under the impression that it was suproxin) or given no information at all
- Control group was given false effects but otherwise remained tested under same conditions
- During this time, participants were observed for changes in emotion
- Participants were then asked to fill out a questionnaire detailing their state of emotion
- Showed that participants that were given information on the effects of adrenaline showed minimal changes in emotion
- But those who had been told no effect, thus no explanation for their state of arousal showed much higher changes in emotion (in regards to the scenario they were in)
- Participants who received a placebo experienced no state of arousal and this had no need to explain their feelings through their surroundings tho they had minimal changes in emotions
- Those who were misinformed about the effects of adrenaline were included for control purposes and so their results were not included
- Researchers concluded that emotion occurs by a process of cognitive labelling: the interpretation of physiological cues is combined with contextual cues to construct a person's subjective experience of emotion. *When explaining this study, do not go this much in-depth as in the above. State only the most relevant things that the examiner should know.
- This study shows that adrenaline can contribute to changes in emotion, a behaviour expressed by humans.
- Outline testosterone
- A second hormone which can affect human behaviour is testosterone.
- Secreted by the testes in males
- Explain the functions of testosterone
- Testosterone is mainly known for supporting male traits as it influences aggressiveness and aggression in general.
- In males, it is responsible for factors such as:
- The deepening of the voice
- Facial hair growth
- Increasing overall body mass and size of the male’s penis and testes.
- Responsible for maintaining a male’s sex drive. o
- Although linked profoundly in males, testosterone is also found in females.
- It plays a less important role
- Secreted in small amounts from the ovaries
- Stimulates the production of red blood cells.
- Increases the incorporation of amino acids & protein synthesis in muscles, liver, & kidneys, thus stimulating their growth & metabolism.
- Increases cell division in certain tissues.
- Essential for reproduction & maintenance of male characteristics, organs & behaviour
Study 2: Arnold Berthold (1849)
Introduce Study - Signpost
- An early indication of a study demonstrating the effects of testosterone on animal behaviour is a study conducted by Berthold (1849).
- The aim of this experiment was to test the effects of testosterone through the castration of roosters.
- Quasi Experiment
- 6 healthy roosters
- Surgically castrated them (removing testicles thus stopping the production of testosterone)
- He then divided them into 3 groups of 2 roosters
- Group 1 - control group- roosters were left in their own capons
- Group 2 - transplanted with testicles of another rooster
- Group 3 - reimplanted with their own testicles
- Berthold observed that the castrated roosters displayed different behaviour, where they were less masculine and less aggressive towards other roosters.
- Such behaviours included a lack of crowing, fighting, and showed a less desire to mate.
- Those roosters that reacquired testicles behaved like normal roosters again.
- Autopsy of roosters revealed that the testicles did not re-establish nerve connections with the rest of the body.
- Berthold concluded that the testicles must have produced a biochemical that influences aggression and dominant male behaviours.
- This study relates to the function of testosterone because when roosters had testes (which secrete testosterone) they displayed dominant male behaviours and aggression.
- However, when they were removed it showed that the evolutionary and dominant “male? behaviours of the roosters (aggression) decreased, which indicates the connection that testosterone affects behaviour.
- Because he tested the effects of testosterone on animals but not humans, some people may argue that his findings cannot be generalised to humans.
- Although this is the case, Berthold still found significant results relating to the influence of testosterone and was a good early indicator, which generated more research into this biological area into humans.
Study 3: Dabbs et al. (1995)
Introduce Study - Signpost
- A further study supporting the effects of testosterone in humans was by Dabs et al. (1995)
- The aim of this experiment was to investigate the relationship between testosterone and both sex and aggression.
- They explored the relationship between testosterone levels and types of crimes committed by 692 prison inmates.
- Men who had committed personal crimes involving sex and violence had significantly higher testosterone levels than men who had committed property crimes.
Study 3: Dabbs & Morris (1990)
Introduce Study - Signpost
- In another study, Dabbs and Morris (1990) investigated...
- The relationship between testosterone, sex and aggression and its effects.
- Previous studies into the relationship between testosterone, sex and aggression have been limited by small sample sizes and failure to control effects of social class.
- Quasi Experiment
- Used a very large sample = 4,462 that were representative of American men in race, education, income and occupation.
- All had been enlisted in the US army and had been followed longitudinally from 1985 as part of a study of the effects of the Vietnam military experience.
- Men’s testosterone levels were measured during their induction into the Army.
- Extensive information relating to the men’s sexual behaviour, aggressive and criminal behaviour, and social class (education and income) since their discharge from the Army was collected.
- First, they found an association between testosterone levels and SES: low SES men were significantly more likely than high SES men to have high testosterone levels.
- Second, men with high testosterone levels were significantly more likely to have been involved in childhood delinquency, adult crime, hard drug use, marijuana use, alcohol abuse, to have gone AWOL in the army, and to have had “many sex partners.?
- Dabbs and Morris also found the relationship between testosterone levels and these outcome variables differed by social class.
- Dabbs found that a higher socio-economic status moderates the effects of testosterone on criminal behaviours. He argues that persons of greater social status have access to other ways of expressing dominance than simply aggression. Therefore, they are less likely t end up in criminal trouble.
- Men with higher income and more education were, on average, significantly less likely to have high levels of circulating testosterone than men with low income and less education. Only in those men with lower socio-economic status was there a tendency for high levels of testosterone to be linked to antisocial behaviour.
- Dabbs and Morris concluded that testosterone has many profound effects, especially on male behaviour.
- This study relates to the simplistic view that testosterone leads to aggression and violence, and various other aspects of behaviour in humans, such as antisocial or prosocial behaviour.
- It establishes that testosterone has almost the same effects in both animals and humans because of similar biological processes and evolution.
- Testosterone affects behaviour, but the outcome of behaviour also affects testosterone levels.
- Both hormones show considerable influence into human behaviour.
- State significance of supporting studies into effects of hormones on behaviour:
- Both hormones are supported by valid studies, proving that these hormones do in fact have an effect on human behaviour.
- Outline/state the connection between the BLA overarching principles and hormones
- Behaviour has physiological origins.
- Hormones are a biological factor contributing to behaviour.
- The relationship between physiological factors and environmental stimuli is bi-directional.
- Hormone levels are affected by the environment.
- There are biological correlates of behaviour.
- Research has identified specific hormones with specific behavioural functions.
- Example: TestosteroneAggression
- Cognitions, emotions and behaviours are products of the anatomy and physiology of our nervous and endocrine systems.
- Hormones are produced by the glands of the endocrine system.
- Animal research provides insight into human behaviour.
- Much research on hormones has been conducted on animals and extrapolated to humans to find the correlation between hormones and behaviour.
- Concluding Statements and assumptions
- Therefore a bidirectional relationship exists between hormones and behaviour, where hormones affect behaviour and behaviour feeds back to affect hormones.
- Hormone-behaviour relationships are complex.
- It is NOT appropriate to say that hormones “cause” behaviour rather that hormones change the probability that a particular behaviour will be displayed.
- Therefore, hormones simply influence behaviour.