Negative Probability Ions question

Are Negative Probability Ions different depending on the person?

So like, in Phineas and Ferb it's been confirmed that Candace and Doof are surrounded by Negative Probability Ions The difference between them and the Murphy's is that the Negative Probability that the Ions cause seem to affect them specifically, which is different from the Murphy's as Negative Probability for them affects their environment, not them just them specifically so, what exactly causes this?