Daniel Kahneman’s peak-end rule in product experience

Background - What is the Peak-End rule ?

The Peak-End rule is a psychological phenomenon first proposed by Daniel Kahneman. According to the rule, people tend to remember experiences based on the peak (most intense) moment of the experience and the end of the experience.

The rule has been found to be applicable in various contexts, including pain, pleasure, and emotional experiences.For example, in the context of pain, patients who experienced a shorter duration of pain but with a more intense peak reported less discomfort overall compared to patients who experienced longer pain but with a less intense peak.In the context of pleasure, a study found that people who listened to music with a more pleasurable peak and a pleasant ending rated the experience as more enjoyable overall compared to those who listened to music with a less pleasurable peak and an unpleasant ending.

Similarly, in the context of emotional experiences, individuals tend to remember events based on the peak and end moments of the experience, rather than the overall duration of the experience.

How can a designer apply this rule ?

Let’s look at how Zomato’s tipping experience is a perfect example to see the peak-end rule at play.

The reward for tipping the agent is not monetary, but rather psychological. As social beings, we are wired to respond positively to reminders that we are adhering to pro-social behaviour. In this case, the user is being validated by Zomato for his tipping decision. This reminder can feel good and be rewarding in itself.

Peak-End Rule at Play : The end of the entire experience is at a good note which validates the user for his/her pro social behaviour. A strong emotional note to end the experience on.

My attempt at conducting the experiment and gather results

As a part of my master’s course in Cognitive Science, I was taught about different experiments and the theories that emerged from them. But I wanted to get my hands into these experiments and see for myself what the results look like.

In this study, I aim to test the applicability of the Peak-End rule on images. Specifically, I used neutral and happy images to see if people remember the images based on the peak and end moments.

Study Design

I conducted a study using 10 trials and one practice trial for each participant. Each trial consisted of 10 images. Five of the trials were randomly chosen to satisfy the peak-end positioning of happy images, and the other five were randomly shuffled images. Participants were asked to rate the overall emotion sensed from the trial images on a scale of 1-10, where 1 meant neutral emotion and 10 meant happy.

I used AI generated images of 10 different female models to control for gender. All images had same background colour to rule out any possible correlation of emotion sensing to specific colours.

Experiment Demo

Results

From data collected for 5 participants, 10 trials each, I had a total of 50 ratings.
On calculating the mean ratings for randomised display of image sequence vs peak-end rule satisfying display of image sequence, there was a clear difference between ratings for both conditions for each participant.