Testing Beliefs Through Action

Lucy held the core belief that she was dull, assuming others would find her uninteresting. Because socialising caused her anxiety, she frequently used a 'safety behaviour': asking others constant questions to hide her own perceived lack of personality.

We all maintain internal beliefs about ourselves and the world. However, if these beliefs are inaccurate, they can negatively dictate our thoughts, emotions, and actions. Lucy’s therapist challenged her to consider: "What would happen if I stopped asking so many questions?" To find the answer, Lucy realised she had to test her assumption in the real world.

The Scientist’s Approach

A helpful way to view this is by mimicking how scientists work. They treat their beliefs as 'hypotheses' — educated guesses rather than established facts — and remain open to new evidence. They then design experiments to see if those guesses hold up under scrutiny.

How This Tool Supports You

The Behavioural Experiment worksheet is designed to help you:

• Collect fresh, objective data.
• Scrutinise the validity of your beliefs and predictions.
• Experiment with new ways of acting or abandon habits that restrict your progress.

How to Use the Worksheet

Complete the first two sections while planning your test, and the final two sections once the experiment is finished.

• Prediction: State the specific assumption you want to test and define what 'failure' would look like. Rate your belief in this outcome from 0–100%.
• Example: Lucy predicted that talking about herself would cause others to become bored. She decided she would know this had happened if people yawned or walked away while she was speaking.
• Experiment: Outline a clear plan to test your belief.
• Example: Lucy planned to talk about herself with at least five different people at a party while observing their reactions for signs of boredom.
• Outcome and Learning: Carry out the plan and record the results. Re-rate your belief in the original prediction (0–100%) based on what you discovered.
• Example: After speaking to six people, Lucy noted that no one yawned or left abruptly. She concluded, "I can be interesting sometimes," though she felt she needed more evidence to believe it fully.
• What’s Next? Consider further tests or other beliefs to investigate.
• Example: To ensure her success wasn't just a 'fluke', Lucy decided to repeat the experiment in different social settings.

Behavioural Experiments can be adapted and modified to fit specific use cases. For example, two extra columns — Uncertainty Beliefs and Coping Responses — can be added for someone who has difficulty coping with uncertainty. You can see a couple of examples of how this looks in practice here.

Before completing your own worksheet, take a look at the filled in example below.

This Behavioural Experiment worksheet template comes courtesy of Psychology Tools.