Describe (or outline) one study that demonstrates how one hormone affects human behaviour. Hormones are produced by endocrine glands ad released directly into the bloodstream. Adrenaline is a hormone that affects human behaviour. It is secreted in the Adrenal glands, and is responsible for the flight-or-fight response. The Schater and Singer (1962) study’s aim was to test the theory of emotion (that emotion arises from a combination of a cognition and arousal), using the hormone adrenaline. In this study, participants were informed they would receive a vitamin injection for vision experiments, but they were actually given adrenaline (to reduce participant bias). Test had 184 college males, through opportunity sampling. They were then split into 4 groups. Group 1-3 received adrenaline; group 4 (control) received a placebo solution. Group 1 was told the effects of an adrenaline solution (described as side effects to the vitamin solution), group 2 and 3 wasn't given any info. The control group was given false effects but otherwise remained tested under same conditions. The participants completed a questionnaire with personal questions, to see whether the participants would get angry. They also took part in activities in an office space. These activities were encouraged by Confederated (research actors). The results showed that participants that were given information on the effects of adrenaline showed minimal changes in emotion. Participants who received a placebo experienced no state of arousal. Groups 2-3 generally showed more euphoric behaviour and reported more happiness. The researchers then concluded that adrenaline helps in the construction of the emotional experience. And helps in a real-life situation the surge of adrenaline would assist in appraising a situation to establish a proper emotional response. In conclusion, adrenaline affects human behaviour. This study shows that adrenaline can contribute to changes in emotion. But a weakness is that the experiment definitely lacked ecological validity. We do not usually experience emotions in the way in which Schachter and Singer induced them. And the study can also be questioned on ethical grounds. Even though the participants were given health checks before the experiment began, and were thoroughly debriefed, they were considerably deceived.