A recent article published in the journal Frontiers in Psychology in 2015 examined the effects of two very different scents on interpersonal trust.
Trust is a crucial element in many social settings. Think of what relationships, business deals, employment, marriages and family would be like without trust.
However, like many other cognitive processes, trust can be manipulated by factors outside of our conscious control.
One experiment conducted in the Netherlands found that whether we trust another person can even be influenced by scent. Understanding how different scents can influence how other people think (and how we ourselves think) can give us an edge in a number of areas.
Different scents are associated with different physiological states.
Some scents seem to get people excited, aroused, hyped up, etc.
One strongly exciting scent for humans is peppermint.
Other scents seem to be associated with calmness, relaxation, and rest.
One example here is lavender.
Possibly, calming/relaxing scents (like lavender) can promote trust between people.
On this theory, if you are more relaxed and calm around others, this may influence your thinking.
The opposite may also be true. Exciting/arousing scents (like peppermint) might promote individualistic thinking and less interpersonal trust.
The researchers recruited 90 participants to be in this study.
Before the experiment, all participants did a phone survey to assess their general psychological state.
Then, all participants completed the experiment in pairs (separated into two cubicles) in a special room.
30 participants did the experiment in a peppermint-scented room.
30 participants did the experiment in a lavender-scented room.
30 participants did the experiment in a room with no aroma.
At the beginning of the experiment, all participants did a kind of mood survey to assess how they were feeling in the room.
The researchers also measured the participants’ psychological arousal (not sexual arousal – just general physical excitement).
All participants then did a trust game that is often used to measure interpersonal trust.
Participants were told that they’d be playing against the other person in the room (in the other cubicle). In reality they were not playing against each other.
Here are the rules of the game:
Each person is told they’d be given 5 Euros.
- They have the option to keep the money, and in that case they’re given the money and the game stops.
- However, they also have the option to “transfer” SOME or ALL money to the other player, which triples the amount of the transferred money (3 Euros changes to 9 Euros).
- The other player then can split up that money however he/she wants between him/herself and the original player.
- So a trusting participant would choose to transfer more money, thinking perhaps that the other player would fairly distribute the money and both would get a larger amount.
Example: Perhaps a trusting participant would keep 2 Euros and transfer the remaining 3. The 3 Euros that are transferred change to 9 Euros. Then the second player might split that money 50/50 and send half back. So the first player ends up with 6.50 instead of the original 5.
This player is trusting that the second player will fairly distribute the money, and both will benefit.
- A non-trusting participant might be afraid that the other person would keep all the money or give them an unfair portion. They might want to take the initial amount – a smaller, guaranteed amount is better than trusting another person with a larger amount.
- Remember, the pairs of participants weren’t actually playing each other. The experiment simply measured whether a person chose to transfer vs. keep the money and how much.
The mood survey revealed that there were no major differences in MOOD for all the participants in the rooms.
- This rules out the possibility that the scent changed their moods, which was the real difference in the game outcomes.
Participants in the lavender-scented room were more trusting (they transferred more money to the imaginary second player) than those in the other two rooms.
Participants in the control (no scent) and peppermint rooms didn’t really differ from each other that much.
The results confirmed one hypothesis of the researchers. Lavender creates a soothing, calming environment that increases a sense of trust.
Peppermint didn’t have the effect they expected – it wasn’t really different than having no scent.
Thus, we have evidence that certain scents (particularly soothing, calming scents) result in more trust between people.
Sellaro, R., van Dijk, W. W., Rossi Paccani, C., Hommel, B., & Colzato, L. S. (2015).
A question of scent: Lavender aroma promotes interpersonal trust. Frontiers in Psychology, 5(1486), 1-5.