Star Trek: 10 Things You Didn’t Know About Dax

Every host of the Dax symbiont can be seen as a new individual—a combination of the newest host and all those who came before. Still, each of their past lives had a small influence on their personality.

For example, Lela would always walk with her arms behind her back, a habit that later hosts maintained. Sisko was particularly surprised by how similar Jadzia was to his old friend, Curzon, the previous host. Jadzia maintained his love for Klingon culture and gambling, as well as his friendship with Sisko. Some traits would not be passed on to new hosts, for example, Tobin Dax bit his nails frequently, but no other hosts did. It's largely unpredictable what habits will be kept.

Unfortunately, unwanted personality traits could also be passed on, like the host Joran's murderous tendencies, but the most extreme of these traits could be suppressed with practice.