Draw the diagram of the theory of planned behavior but add one more factor before drawing.

The Theory of Planned Behavior (TPB) is a psychological theory that links beliefs and behavior. It suggests that human action is influenced by three main factors: Attitude towards the behavior, Subjective Norm, and Perceived Behavioral Control. To add a fourth factor, we can incorporate "Personal Values" as it can influence both attitudes and intentions.

Here's how you might visualize the TPB with the additional factor:

```
                  Personal Values
                       /    \
                      /      \
                     /        \
            Attitude        Subjective Norm
                     \        /
                      \      /
                       \    /
                   Intention
                       |
             Perceived Behavioral Control
                       |
                     Behavior
```

### Explanation:
- **Personal Values**: This represents the individual's fundamental beliefs and principles that play a role in shaping their attitudes and intentions towards specific behaviors.
- **Attitude**: Reflects the individual's positive or negative evaluation of performing the behavior.
- **Subjective Norm**: Represents the perceived social pressure to perform or not perform the behavior.
- **Perceived Behavioral Control**: Refers to the individual's perception of their ability to perform the behavior.
- **Intention**: The intention to perform a behavior is influenced by the three factors above.
- **Behavior**: The actual performance of the behavior based on the intention.

This diagram allows for a clearer understanding of how personal values can interplay with the other components of the Theory of Planned Behavior to influence behavior.