Asked what propositions are worthy of wider debate, Dan McAdams, a professor of psychology at Northwestern University, wondered how humans arrive at their personalities.

He wrote:

I am a personality and life-span developmental psychologist. Thus, my main activities are teaching, writing, and research.  In my field, there are many ideas that are widely and vigorously debated. But it is not clear to me that the public at large is aware of these debates. Actually, “debate” is not quite the right word, because it suggests two diametrically opposed sides who take each other on. A better way to characterize it would be “conversations” among psychological scientists of different persuasions and inclinations, all of whom study the phenomenon of human personality.  We may think of personality as the distinctive set of psychological characteristics that distinguish one person from the next. The back-and-forth among psychologists regarding the nature of human personality draws mainly from scientific research and theory, but it is also informed by ideology, culture, and personal experience.

A central question in the field of personality psychology today is this: To what extent is our personality given to us, and to what extent do we make it ourselves?

This is not the same thing as the old “nature versus nurture” debate. It is not so much about genes and environments as it is about the role of human will in the formation of personality. It seems pretty clear that certain foundational features of human personality – such as our basic dispositional traits – feel as if they are given to us.  For example, as people move through life, from one situation to the next, they do not typically choose to be, say, “extraverted” or “anxious” or “especially kind and considerate.”  “This is just how I am,” an especially extraverted person might say, regarding her tendency to be outgoing and socially dominant.  “I can’t help it, I am just a very nervous person,” an individual with high levels of the trait neuroticism might conclude.  

People tend to feel that their dispositional traits are given to them – by genes, past experiences, luck, whatever.  (And research supports the claim.)  

At the same time, there are other features of human personality that feel chosen or made, such as one’s life goals and values and, especially, the story that a person has constructed about life. Life stories – or what psychologists call narrative identities – are a very hot topic today in the psychological sciences.

A person’s life story is an internalized and evolving narrative of the self that reconstructs the past and imagines the future in such a way as to provide life with some sense of meaning and purpose.  The story provides a subjective account, told to others and to the self, of how I came to be the person I am becoming. With respect to human personality, people’s stories about their lives (their narrative identities) layer over their dispositional traits. To understand a person well, even if that person is the self, one must understand the basic traits that inform everyday social behavior and the inner story that gives meaning to the person’s life.  

The traits are given, it seems; but the stories seem to be made.  Human beings, therefore, are simultaneously social actors whose behavior is shaped by given traits and autobiographical authors who make meaning out of their lives through narratives.

Professor McAdams will try to get inside Donald Trump’s head this week at the Aspen Ideas Festival, co-hosted by the Aspen Institute and The Atlantic. To join the conversation about human personalities and its origins email conor@theatlantic.com.