Fixed or Fluid? Sexual Identity Fluidity in a Large National Panel Study of New Zealand Adults

Sexual orientation has been defined as an enduring aspect of the self, but emerging evidence reveals that people's sexual attractions, behaviors, and identities can shift over time. To examine this possibility, we present a large longitudinal analysis of sexual orientation identity fluidity among New Zealand adults (Ntotal = 45,856; age = 18-99; lesbian, gay, bisexual, and other sexual minority (LGB+) ns = 746-3,387). Over seven years, 5.7% of participants changed sexual identities at least once. Change was bi-directional (i.e. toward and away from LGB+ identities) and most common in people who initially reported a plurisexual identity. Although women reported higher rates of plurisexuality than men, they were not more fluid in their identities, contradicting the notion of male fixedness and female plasticity in sexuality. Moreover, openness to experience was associated with increased odds of changing from a heterosexual to a plurisexual identity, while political liberalism and lower conscientiousness were associated with increased odds of changing from a heterosexual to a plurisexual identity and more identity changes over time. Overall, our study shows that sexual identity can be fluid into adulthood and has implications for how we understand contemporary human sexuality.