It was in an online journal, Psychology Today, by Hal Herzog. Here is the piece of the article:
In their article, Westgarth and her colleagues suggested it is possible that some unknown pattern of behavior in emotionally unstable people makes them especially prone to dog bites. But they also point out that other factors might be involved. For example, anxious people might be more likely to have nervous dogs. Or the causal arrow point could even point the other direction and being bitten by a dog could make people more fearful and anxious.
What does that mean there and why has the definite article been used before that phrase?