Historically, the concept of personality refers to a stable set of dispositional traits and tendencies that describe who a person is and how he interacts with the world. There are several factors that appear to influence personality: genetics and epigenetics; pre-natal/in-utero environment; childhood environment; traumatic events; and psychological development, to name a few. The prevailing view is that personality develops over the course of a person's childhood; by the time a person reaches young adulthood, his or her personality is, for the most part, fully formed. After that, personality change becomes exceedingly difficult and highly unlikely.
I find it interesting that the term "personality" stems from the Latin word "persona," which means mask. This suggests that personality is little more than the various personae people adopt to fulfill certain roles.
While there is undoubtedly some substance to a person's personality, an individual is more than just his or her personality. Think about the different "personalities" we all have: the responsible me who follows rules and fulfills obligations would hardly recognize the lazy me who stays in bed half the day or the carefree me who goes out with friends and dances the night away. Plus, my "preferred way" of interacting with the world frequently changes, depending on my mood. (Sometimes I enjoy a long talk with a friend; at other times I don't feel like talking to anybody).
In her book, "Radical Acceptance," Tara Brach explains that if we sit quietly and observe our internal world we will discover that it is made up of the coming and going of various thoughts and sensations. There is no stable "self" that remains present; the internal "self" is constantly changing from moment to moment.
Almost all spiritual or religious traditions teach that a person is more than just his or her bodily incarnation and its accompanying thoughts, feelings, and sensations. Some refer to the Holy Spirit that lives within each of us. Many refer to a soul that is non-material and distinct from our physical bodies. Still others suggest that the essence of the universe is consciousness; this is also the essence of all living things within the universe. Although various traditions conceptualize it differently, they agree that there is more to a person than what we typically identify as "self."
If you really think about it, this is sort of a radical concept. For most of us, when we refer to our "selves" we mean our personalities. Who among us would disagree that an individual's personality defines who that person is? The fact is, we all need or personalities or "personae" to successfully function in our world. The practicalities of daily life demand it. To survive, we as humans must have a way of interacting with one another that makes sense to us. Personalities meet this need. My personality tells me how I feel comfortable behaving in different situations and helps me to identify effective ways of interacting with my environment in order to get my needs met.
It is important, however, for each of us to remember that we are more than just our personalities. What we call "self" is really just the ever-changing flow of experience. Take your thoughts, for example. We consider our thoughts to be one of the most intimate parts of who we are. Yet if we pause and turn our attention inward, we will notice that our thoughts aren't really "ours" at all.
In his article "No self or True Self," Jack Kornfield (tricycle.com) explains it as follows: "As we look, we find that we neither invite our thoughts nor own them. We might even wish them to stop, but our thoughts seem to think themselves, arising and passing according to their nature."
So what does this mean for us? It means that victims of rape or child abuse can stop viewing themselves as "damaged." What happened to their bodies did not -- COULD NOT -- touch or taint the essence of who they are. It means that people who are depressed can stop telling themselves that they aren't good enough. We are all part of the same flow of experience, all created of the same essence -- nothing we do or fail to do can change that. It means that worriers can stop believing their thoughts. Thoughts are just thoughts. They don't define who we are and are often not even an accurate reflection of reality. Worriers don't have to identify with their thoughts, thereby enabling them to arouse anxiety. They can just allow them to arise and then pass without clinging to them.