Describe the function of one hormone in human behaviour

The hormone oxytocin is produced by the hypothalamus and released into the bloodstream through the pituitary gland and into the brain where it attaches to oxytocin receptors. Oxytocin has been associated with trust and creating a bond between individuals. Baumgartner et al (2008) studied the role of oxytocin during a trust game. The participants played a trust game used by economists and neuroscientists to study social interaction. The participants received either the oxytocin hormone or a placebo. The “investor”  (a participant) receives a sum of money and must decide whether to keep it or share it with a “trustee” (another participant). If the sum is shared the sum, it is tripled. Then the “trustee” must decide if this sum should be shared with the original investor ( to gain their trust) or be kept (violation of trust). An fMRI scan was carried out on the 49 participants to give researchers a 3D, detailed video image of the participants’ brain activity. Participants played against different trustees in the trust game and against a computer in a risk game. In 50% of the games the “trustees” broke the trust between them and the “investor” . Participants then received feedback on this from the researchers during the games. Participants in the placebo group were likely to show less trust after being told about the betrayal and they invested less and didn’t trust the “trustees”. The fMRI scans showed decreases in responses in the amygdala and the caudate nucleus. The amygdala is associated with emotions and emotional processing in the brain. As it has many oxytocin receptors, there is a link between oxytocin and sentiments and your behaviour towards someone will depend on the level of trust you have in that person. The caudate nucleus, a component of the basal ganglia, is linked to memory and plays a role in learning and remembering to trust, which suggests that once the trust was violated, it was hard to trust that person again. Participants in the oxytocin group continued to invest at similar rates after receiving feedback on a breach of trust this can suggest why people are able to restore trust. Participants with higher levels of oxytocin trusted more and continued sharing money, even after being betrayed, suggesting that oxytocin is linked with trust.