UCLA life scientists have identified for the first time a particular gene¹'s link to optimism, self-esteem and "mastery," the belief that one has control over one's own life -- three critical psychological resources for coping well with stress and depression. "I have been looking for this gene for a few years, and it is not the gene I expected," said Shelley E. Taylor, a distinguished² professor of psychology³ at UCLA and senior author of the new research. "I knew there had to be a gene for these psychological resources."

The research is currently available in the online edition of the journal Proceedings⁴ of the National Academy of Sciences (PNAS) and will appear in a forthcoming print edition.

The gene Taylor and her colleagues identified is the oxytocin（催产素） receptor gene (OXTR). Oxytocin is a hormone⁵ that increases in response to stress and is associated with good social skills such as empathy and enjoying the company of others.

"This study is, to the best of our knowledge, the first to report a gene associated with psychological resources," said lead study author Shimon Saphire-Bernstein, a doctoral student in psychology in Taylor's laboratory. "However, we wanted to go further and see if psychological resources explain why the OXTR gene is tied to depressive symptoms. We found that the effect of OXTR on depressive symptoms was fully⁶ explained by psychological resources."

At a particular location, the oxytocin receptor gene has two versions: an "A" (adenine) variant⁷ and a "G" (guanine) variant. Several studies have suggested that people with at least one "A" variant have an increased sensitivity to stress, poorer social skills and worse mental health outcomes.

The researchers found that people who have either two "A" nucleotides or one "A" and one "G" at this specific location on the oxytocin receptor gene have substantially lower levels of optimism, self-esteem and mastery and significantly higher levels of depressive symptoms than people with two "G" nucleotides.

The findings are "very strong, highly significant," Taylor said. The study has important implications.

"Sometimes people are skeptical⁸ that genes⁹ predict any kind of behavior or psychological state. I think we show conclusively¹⁰ that they do," said Taylor, who is a member of the National Academy of Sciences and directs UCLA's Social Neuroscience Laboratory.

She stresses, however, that while genes may predict behavior, the do not determine it.