Can a shark be introverted? A new study from the University of Exeter suggests that at least one species of shark can be. Researchers found that the small-spotted catshark seems to display individual character variations that are more commonly associated with humans.

In general, these sharks, which are sometimes referred to as lesser-spotted dogfish, tend to rest in piles on top of one another on the sea floor. However, during a series of experiments involving captive juveniles at the Marine Biological Association in Exeter, England, some individual sharks routinely shunned the group, instead choosing to rest by themselves.

The researchers repeated the experiment in three separate habitats, and each time, the same individuals opted to be alone. These more solitary individuals appeared to be less socially connected to their peers than the other sharks, the researchers report in a study published Wednesday in the scientific journal Behavioral Ecology and Sociobiology.

“We found that even though the sizes of the groups forming changed, socially well-connected individuals remained well-connected under each new habitat. In other words, their social network positions were repeated through time and across different habitats,” behavioral ecologist David Jacoby explained in a statement Wednesday.

Does this mean that sharks have personalities?

It depends on how you define personality. The researchers define it as a repeatable behavior across time and contexts that varies among individuals. By that definition, it does seem that small-spotted catsharks – at least juveniles living in captivity – do in fact have a personality. But most definitions of personality are much more nuanced than that.

Merriam-Webster, for instance, defines personality as “the totality of an individual’s behavioral and emotional characteristics.”

Most of us would object to having their personality defined by just one particular trait, such as introversion and extroversion. Can a brooding recluse really be said to have the same personality as a trusting wallflower just because both individuals are introverted?

The dominant model in contemporary psychology describes personality according to the so-called Big Five factors: extroversion, agreeableness, conscientiousness, neuroticism, and openness to experience. This particular study examines just one of these dimensions.

There is a wide body of evidence suggesting that many members of the animal kingdom do have their own character traits. Most pet owners attribute a whole host of personality traits to their cats, dogs, and even their fish.

Humans experience the world through their own emotional filters. It can be difficult not to impose those emotions on the animals in our lives. For instance, dog owners frequently talk about their dogs assuming a guilty pose after swiping food or knocking over the garbage can.

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But animal behaviorists insist that the supposed guilty-puppy look of droopy eyes and lowered head is a learned response to their master’s displeasure rather than any internal awareness of having done something wrong.

Whether dogs' efforts to appease their masters reflect a desire for affection or a survival tactic is a matter of interpretation. When talking about animals, the distinction between instinctual behavior adaptations and defined character traits become blurry.