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Aromatic Substance Hedione Influences Human Behavior

New study indicates amplification of reciprocity

Two economists and a cell physiologist from the Universities of Bern, Cologne, and Bochum have conducted a pioneering laboratory experiment on the effects of the aromatic substance Hedione on human behaviour. Hedione has a ligand for a human pheromone receptor, which suggests that it may influence behaviour in humans in a way similar to animal communication via pheromones. The study showed that Hedione does in fact amplify reciprocity in humans. However, further research is necessary to clarify the role pheromones play in human behaviour.

It is disputed whether humans communicate via pheromones the way animals do. An interdisciplinary study conducted by a cell physiologist and two behavioural economists from the Universities of Bochum, Bern, and Cologne has now made an important step towards resolving this question. The study suggests that Hedione, an aromatic substance with a flowery scent, influences human behaviour. In laboratory experiments, the scientists found out that Hedione amplifies reciprocity, that is, a ‘tit for tat’ sort of behaviour. These findings are particularly relevant because earlier research has identified Hedione as the only aromatic substance that has a ligand for the human pheromone receptor VN1R1. This activates a region of the brain that is involved in hormone regulation. Interestingly, this effect is ten times more pronounced in women than in men. (See also Ruhr-University Bochum’s press release:

These new insights on the effects of Hedione have now been published in the journal Frontiers in Behavioral Neuroscience by the economists Sebastian Berger (University of Bern) and Axel Ockenfels (University of Cologne), and the cell physiologist Hanns Hatt (University of Bochum). 

In the experiments, people under the influence of Hedione reacted to other people’s trust with an increase in trustworthiness. When other participants in the experiment did not behave cooperatively, they tended more strongly to punish them. ‘Our test persons reacted in a slightly friendlier way to friendliness and in a slightly unfriendlier way to unfair behaviour’, says Sebastian Berger. These changes in reactions could be noted when the scent of Hedione was present in a room – in comparison to situations in which there was no scent at all or a different floral control scent. The concentration of the scents was so low that the test people did not consciously perceive them. 

Whether people actually communicate via pheromones the way animals do is disputed, however. ‘The results of our experiment might indicate that humans also exhibit a reaction to pheromones that is different from our classic sense of smell’, says Hanns Hatt. Axel Ockenfels is convinced that ‘reciprocal behaviour is vitally important for human interaction because it facilitates cooperation. That is why it is at the centre of many behavioural models in evolutionary biology and other disciplines researching the origins of cooperation.’

‘Our study is a first step towards promising cooperation among cell physiologists and behavioural scientists. We now want to test the robustness of our results in other behavioural settings and identify the underlying mechanisms’, the researchers explain. It is also important to identify natural scent molecules in bodily secretions that are similar to Hedione, with a similar effect on the pheromone receptor. In order to find conclusive evidence of human communication via pheromones, the researchers first have to identify an odour produced by humans that produces a specific, reproducible reaction in other human beings. However, the state of research is still far from that point. The scientists nevertheless hope that their work will encourage further interdisciplinary studies in order to identify the role pheromones play in human behaviour.

Original publication: Sebastian Berger, Hanns Hatt, Axel Ockenfels: Exposure to Hedione increases reciprocity in humans, in: Frontiers in Behavioral Neuroscience, April 2017, doi:10.3389/fnbeh.2017.00079

Professor Sebastian Berger
Department of Organization
Department of Organization and Human Resource Management
University of Bern
Mail: sebastian.berger(at)

Professor Axel Ockenfels
Department of Governance and Public Policy
Faculty of Management, Economics and Social Sciences
University of Cologne
Mail: ockenfels(at)

Professor Hanns Hatt
Department of Cell Physiology
Ruhr-University Bochum
Mail: hanns.hatt(at)