Human behavior is one fascinating subject. Below is a basic outline & URL to the site. You look at all the contributing areas...throw in the complexity of a emotional based illness as BPD...& "god-dam" the sky's the limit to what your behavior is at any set time. Most of these factors...are always changing...one's environment changes...there is no answer to the "allusive truth" of human behavior.
http://library.thinkquest.org/26618/ Psychology of behavior
Theory of behavior
Basic drives and motives
Social influences
Emotions
Biological base of behavior
The nervous system
Genetic influences
Influences of hormones
Biological rhythms
Daily behavior
Gestures
Influencing daily behavior
Body language
Examples of body language
Reading body signals
Behavioral disorders
Defining abnormal behavior
Addiction
Split-brain
Personality disorders
Alzheimer's disease
Autism
Phobias
Cognitive Processes
Mental representation
Memory
Language
Intelligence
Learning
Dr. Clinically Dead ,
Joe Buck (Bob)