When we are younger, we do see things in all black and white..all good or bad. As we develop properally, we learn to see the shades of gray and understand that people are not all good or all bad. We learn to "remember" a mix of behaviors that a person has, so if they do something "bad", we can still remember the "good."

In splitting, what happens is a person generally sees someone in an idealized position, nothing is wrong with that person. If the person does one thing that upsets the Borderline, usually related to a perceived abandonment, that person becomes all bad. The borderline can not "recall" previous good experiences with that person. In the splitting, the borderline relates to people as they last remembered them, which is usualy idealized or devalued. Borderlines can not hold onto mixed memories.

Scientists would probably tell you that a person can NOT be Borderline without displaying a fear of abandonment. Now, there are various levels of this fear. For example, in therapy, some borderlines will become suicidal at the thought of their therapist going on vacation, whereas other Borderlines might act-out as a two year old with a tantrum, whereas another Borderline might miss appointments.

Hope this helps.