New research suggests that dolphins in the wild can be really shy.
The study - which has been going on for 16 years - has found that bottlenose dolphins display either dominant or shy personalities in their groups.
Personality is really important to the dolphin social system because scientists think it impacts on their ability to find food.
Bold dolphins are more useful for their group because they can spread important social information - including knowledge about where's a good spot to get some food.
The study - which followed a wild population of bottlenose dolphins in Italy's Gulf of Aranci - also found out that the more confident dolphins have stronger social relationships within their group.
Saying that though, dolphins aren't that well known for sticking around.
They spend their time in "fission-fusion" societies. The "fission" part means they are continuously splitting up and joining other social groups.
However, the "fusion" part means they can always come back.
The scientist working on the study, Diaz Lopez, measured dolphin personality by evaluating responses to challenging situations.
An animal with a bold personality is more likely to approach an interesting object or investigate a potential predator than one that is shy.