Are they MADE or Born?

Childhood experiences may play a major role, but most experts agree that both high levels of narcissistic traits and NPD arise from the combined influences of nature and nurture that likely begin in the genes. “There are personality traits we come into the world with,” says Kali Trzesniewski, a social- development psychologist at the University of California, Davis. One’s environment can either weaken or strengthen those traits, “though there are always people who don’t seem to react to their environment; they’re just kind of resilient to it.”

One twin study found that narcissism was a highly heri-