Hello, I’m Wang Fang. At the start of a new week, greetings to you listening now. The Q&A is over, and we return to our course with Part Two.

Part One used personality traits to describe who I am. Part Two focuses on the next question:Where did I come from?

It askshow personality arises, orwhat made us who we are today.Across the history of thought and science, one fierce and enduring controversy has been nature versus nurture. This elegant pairing coined by the brilliant British polymath Francis Galton remains unresolved today.

On one side, experts in bestselling self-help books about raising outstanding children offer earnest advice, embedding the belief that family upbringing determines personality and even achievement. On the other, worldwide consumption of drugs treating psychological disorders and emotional distress has risen sharply in the twenty-first century. If drugs act on the brain and nervous system and alter emotional states, thought, and behavioral responses, do they also change personality slightly? If so,how should we understand the forces shaping personality—as biological or sociological?

I do not intend to take sides. Abundant scientific evidence shows that both extreme biological determinism and extreme environmental determinism are biased. Human beings are neither blank slates awaiting the environment’s inscription nor blueprints fully planned at birth and merely waiting to unfold. We need instead tounderstand objectively how biological and social factors, and their combined force, affect personality. This is more meaningful than endlessly debating nature and nurture.

In Part Two, I will follow two paths toward the origin of what makes the unique you unique. One isbiological, proceeding from proximal to distant causes: physiology, genetics, and evolution. Our immediate physical structure may be inherited, and heredity carries the legacy of long evolution. The other path issociological, briefly considering how family, culture, and the social-ecological environment influence personality formation and change. These paths are neither opposed nor separate; we discuss them one by one only for clarity. Together, through intricate interaction, these forces shaped us into who we are today.