Well its not on purpose, that’s for sure. People with BPD experience and also display emotions more intensely than most other people do. Why is that?
This has to do with two areas of the brain that are involved in emotion processing. The limbic system, located deep in the brain, is where raw sensory information is stored and where primal emotions originate. The so-called ‘fight or flight” reactions are generated from here. It turns out that people with BPD have more activation of the limbic system than other people.
At the same time, people with BPD have less activation in the prefrontal cortex, the area of the brain where thinking, planning, memory and judgment occur- skills that enhance one’s ability to live in social groups.
BPD researcher and psychiatrist Antonia New shows how this under-activity can lead to emotional and social difficulties.
And here is a well written explanation of the brain activities that occur in BPD by Kristalyn Salters-Pedneault, PhD, an expert on Borderline Personality Disorder.