Pisces and psychopaths: is there something common in their behavior?
At first glance, humans and animals no longer seem to have more in common than the taxonomic kingdom to which they belong. However, a new study has revealed something that totally contradicts this belief. After applying a personality test used to identify psychopaths, the researchers discovered the reasons for the differences in behavior among cleaner fish.
The first personality profile of a criminal
When the “Whitechapel Killer”, also known as “Jack the Ripper“Committed crimes in London in 1888, Dr. Thomas Bond made a great contribution to the investigation that has lasted to this day.
In an attempt to identify it, examined the victims in search of clues that could lead them to the identity of the killer. There brutality of the attacks led him to conclude that the killer was a lonely man with a strong impulsive character. This was the first documented time that a criminal profile.
To do this, Dr. Bond assumed that the behavior of an individual was constant over time, which may explain why criminals maintain a similar way of working for nearly all of their crimes. At the moment, these hypotheses are not so well accepted by psychologists. However, police investigations continue to be governed by this premise to reduce their suspect lists.
But there are other tools too, like the checklist Hare psychopathywhich allows you to build the personality profile of a suspect. Based on this theory, the researchers evaluate the likelihood of a person exhibiting psychopathic behavior. This test is also quite useful in criminology, but its application goes further. The same method is used for identify health risks in some individuals (based on their personality and behavior), for example. Also in hiring staff in a company, developing educational programs and even creating dating applications.
And although all of these uses are limited to humans, the researchers have decided to test it in the animal world as well. In their new work, they applied it to understand varied behavior among cleaner fish of the Cyclopterus lumpus species.
Clean cleaner fish ignore salmon, but some take good care of them
The situation is the following. As the name suggests, cleaner fish remove and eat parasites from the skin of other fish. In fact, they are used in aquaculture to control sea lice. This is why every year on the farms of salmon millions of juvenile cleaner fish are released.
However, only 20% of these are actually dedicated to ridding salmon of sea lice. The remaining 80% simply ignore it or end up competing for food. Based on Hare’s list, they designed a series of behavioral tests to build detailed personality profiles for cleaner fish. These covered aspects such as activity variation, aggression, anxiety, courage and sociability, as well as their interactions with the salmon.
Human behavior profiles also work for some fish
In this way, the researchers discovered why most cleaner fish either completely ignored salmon or had very little interactions with the species. As in humans, the personality had weight. Cleaner fish with “bold and non-aggressive” personalities spent long periods of time doing their job: inspecting salmon cooperatively. Thanks to this, they were able to eliminate marine lice and reduce parasites from farms. Conversely, those with “active and social” personality profiles made the salmon flee.
This will certainly have implications for farms, which should start to be more selective about the fish they put in. But the discovery is actually much more significant. Science has confirmed that the creation of personality profiles used in humans also works in fish.