IB Psych Revision: Oxytocin - The Prosocial Hormone?

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Aim: Does oxytocin affect trust in humans?
Method: Humans were given either oxytocin intranasally or a placebo
The independent variable was what chemical the humans received
The dependent variable was their behavior in a trust game: do you trust the investor?
In the trust game the participant was an investor who could choose to invest 4 monetary units and possibly get 12 monetary units in return
Results: The oxytocin group was more willing to trust the investor
Conclusion: This suggests that oxytocin increases our feelings of trustworthiness in others
Evaluation: The participants did not earn the money they used in the study
You can argue that people are more careful with money they have earned themselves
They did a follow up study to ensure that oxytocin was not just increasing riskier behavior

Aim: Does oxytocin affect empathy in humans?
Method: Humans were given either oxytocin intranasally or a placebo
The independent variable was what chemical the humans received
The dependent variable was their performance on an empathy test called the reading the mind in the eyes test

put reading mind in eyes test pics here

Participants took the reading mind in eyes test before the spray and one week later after they were given the spray
Results: Oxytocin group scored higher on the reading mind in the eyes test
Conclusion This suggests that when oxytocin levels are elevated we become better at reading the emotions in people's eyes
Evaluation: Well-controlled study that established a baseline of empathy for all participants before administering the spray
Is the reading the mind eyes test the best measure of empathy?
Empathy is related to feeling what others may be experiencing and not just reading emotions from eyes
The study therefore lacks some external validity

Aim: Do people with different oxytocin producing genes have different empathy capacities?
Method: They compared two gene groups AA/AG genes have low oxytocin and GG genes produce more oxytocin
The independent variable was the gene group
The dependent variable was their performance on the reading the mind in the eyes test
Another dependent variable was their trait empathy measured by a questionnaire
Results: The GG group scored higher on the reading the mind in the eyes test
The GG group also scored higher on the empathy questionnaire
Conclusion: Naturally higher levels of oxytocin produced by your genes increases your empathy level
Evaluation: Well-controlled study that used 2 measures of empathy to establish a cause and effect relationship between the genes and empathy
Is the reading the mind eyes test the best measure of empathy?
Empathy is related to feeling what others may be experiencing and not just reading emotions from eyes
The study therefore lacks some external validity
To add external validity researchers could give participants the opportunity to help someone else in distress which would be a more ecologically valid way of measuring empathy

Aim: Does oxytocin increase generosity to strangers?
Method: Give participants oxytocin or a placebo intranasally and have them split money
The independent variable was whether participants received placebo or oxytocin
Participants are given 10 USD that they can choose to split with a stranger of keep for themselves
The dependent variable was how much participants gave to the stranger
Results: Oxytocin group gave larger amounts to the stranger, they were 80% more generous than the placebo group
Conclusion: Having higher oxytocin levels can increase generosity in humans toward strangers
Evaluation: Well-controlled study to establish a cause and effect relationship between oxytocin and generosity
Lacks some ecological validity because the participants did not have a normal social interaction with the strangers

There is a problem of reductionism. Most research on oxytocin focuses only on positive social behavior
There is evidence that oxytocin can actually lead to antisocial behavior
Participants who were given oxytocin and won a game where more likely to gloat (Shamay-Tsoory et al., 2009)
The participants were happy about the opponent losing and rubbed it in their face
Oxytocin has been suggested as a treatment for antisocial behavior like autism
Shamay-Tsoory's work shows that it is important not to assume that oxytocin is exclusively positive