Biological - Hormones (experiments) Flashcards
Romero et al (2014) aim
○ The role of oxytocin in social bonds
Romero et al (2014) design
○ Sample
§ 16 dogs
Romero et al (2014) procedure
§ The dogs were sprayed intranasally with
□ Oxytocin
□ Placebo
§ They were placed with their owner and another dog in the same room.
§ Their behaviour was recorded by 4 cameras in the room for one hour.
§ The owner sat on a chair as the only object of the room.
Every 10 minutes the owner moved their chair to a pre-determined spot and not interact with the dog.
Romero et al (2014) results
○ Dogs sprayed with Oxytocin
§ Showed higher affiliation to their owner.
□ Sniffing
□ Licking
□ Gentle touching of nose or paw
□ Play Bouts
□ Body contact
§ Spent significantly more time in close proximity of the owner.
Spent more time affiliating with the other dog.
Romero et al (2014) conclusion
○ Oxytocin promotes social bonds and plays a role in maintaining close bonds in mammals.
Kosfeld et al (2005) aim
Investigate the role of oxytocin in increasing trust in humans.
Kosfeld et al (2005) design
○ Sample
§ 128 Male healthy students.
§ Mean age 22 years
Kosfeld et al (2005) procedure
§ The subjects were sorted into a oxytocin group and placebo group.
§ Substances were administered intra-nasally.
§ The player were to play a trust designed game with real monetary stakes.
§ Game
□ Subjects were paired up anonymously.
□ They played the role of investor or trustee.
○ The experimenter gives both the investor and the trustee and endowment of 12 monetary units.
○ The investor then needs to decide how much of that to send to the trustee.
§ There are 4 options
□ 0
□ 4
□ 8
□ 12
○ The experimenter triples whatever is sent to the trustee.
○ The trustee then decides how much they wish to return to the investor.
○ Participants played the game four times in the same role, each time paired randomly with a new partner.
○ At the end of the experiment the total earned units were exchanged for real money.
Kosfeld et al (2005) results
○ The level of trust in the people who received oxytocin were higher than the placebo.
○ 45% of the oxytocin group showed complete trust.
21% of placebo group showed complete trust.
Kosfeld et al (2005) conclusion
○ The researchers put up two explanations
§ Oxytocin reduces risk aversion in general.
§ Oxytocin increases trust in people.
○ The researchers repeated the experiment with a oxytocin group and a random software generator based on transactions of trustees.
○ The final conclusion from the results of the second experiment lead to conclude that oxytocin specifically increases trust in interpersonal interactions.
Scheele et al (2012) aim
○ Investigate the role of oxytocin in fidelity.
Scheele et al (2012) design
○ Sample
§ 86 heterosexual men.
§ Relationship and marital status were varied.
○ Double blind Independent measures design
Scheele et al (2005) procedure
§ Subjects participated in two tasks.
§ Stop distance paradigm
□ Subjects were positioned at the end of the room.
□ Their toes lined up with the starting mark.
□ On the other side of the room was an attractive female experimenter.
□ The subjects was required to move towards the experimenter until they felt too uncomfortable.
§ Approach-Avoidance task
□ Subjects viewed a series of pictures on a screen.
□ Pictures were flashed for two seconds each 50 cm from their eyes.
□ There were four types of photos
® Positive social - Attractive Women
® Positive Non-Social - Beautiful landscapes.
® Negative Social - mutilations
® Negative Non-Social - Dirt
□ All participants had a joystick.
□ They were instructed to push the joystick for dislike and pull if they liked it.
Scheele et al (2012) results
○ Stop Distance Paradigm
§ Oxytocin simulated fidelity in monogamous men rather than single men.
○ Approach-Avoidance Task
§ Only group of pictures affected by oxytocin was positive social (attractive women)
§ Monogamous participants with oxytocin had a slower reaction time (pulling the joystick more reluctantly)
Scheele et al (2012) conclusion
○ By selectively influencing men in a relationship to keep greater distance from attractive strangers that oxytocin promotes fidelity.
De Dreu et al (2012) aim
○ The role of oxytocin in defense-motivated non-cooperation.
De Dreu et al (2012) design
○ Sample
102 males
De Dreu et a (2012) procedure
§ Participants were administered with a placebo or oxytocin.
§ There were then split into 3 people groups and told they would be competing against another group.
§ Following this each member of the 3 groups were paired with a member of the competing team to play a round of prisoner.
§ The participants were asked if they would cooperate or compete.
§ The game was modified to work with monetary units equated to real life stakes.
§ Participants were forced to make the choice 5 times.
De Dreu et al (2012) results
○ A player’s defense-motivated non-cooperation is more likely if the groups’ vulnerability is high.
○ It is not influenced by individual vulnerability.
○ Is more likely in the oxytocin condition.
De Dreu et al (2012) conclusion
○ Oxytocin-induced defense-motivated non-cooperation is motivated by the desire to protect vulnerable group members.
○ This reinforces the role of oxytocin in creating bonds with your group members.
○ It also shows how oxytocin can lead to defensive non-cooperation.
De Dreu et al (2011) aim
○ Investigate the role of oxytocin in ethnocentrism
De Dreu et al (2011) design
○ Sample
§ Indigenous Dutch Males
De Dreu et al (2011) procedure
§ Participants were administered either oxytocin or placebo intra-nasally
§ Experiments involved exposing subjects to people:
□ Belonging to their group
® Dutch Males
□ Belonging to an outgroup
® Middle East refugees and German citizens
§ Experiments used “moral-choice dilemmas”
□ E.G the famous trolley problem with the two tracks switched with ingroup and outgroup members. This was achieved by manipulating the name of the people in the trolley problem from Dutch names to Arab or German names.
De Dreu et al (2011) results
○ Under oxytocin males were more likely to sacrifice an outgroup rather than an ingroup target.
○ In the placebo there was no significant difference.
○ This lead to two explanations:
§ Oxytocin promotes ingroup favoritism
§ Oxytocin promotes outgroup derogation
Further analysis of the data showed that compared with placebo oxytocin males were less likely to sacrifice a member of their ingroup but were not more likely to sacrifice an outgroup.
De Dreu et al (2011) conclusion
○ Oxytocin creates an ingroup favoritism.
