Our empathy comes directly from fish

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Humans are the only species that can be moved by a romantic comedy. But they are not the only ones who share emotions with their siblings. A The study was conducted Researchers at the Gulbenkian de Ciência (Portugal) Institute revealed the chemical mechanisms responsible for the transmission of fear in zebrafish, suggesting that human empathy derives from it.

as As ScienceAlert notes, zebrafish also secrete oxytocin (a hormone synthesized by the pituitary gland). So the scientists investigated the role of the latter in spreading fear in fish. For this, oxytocin receptor-deficient mutants were tested. Since zebrafish release a chemical signal when wounded, the control group and mutants were separated into subsequent pools to avoid biasing the results.

The latter were without appeal: the fish with hormones and functional oxytocin receptors were stunned to see them drowning in misery in the neighboring basin. In contrast, the mutant type does not care about its frightened relatives. Only adding oxytocin to the pool water changed his mind, proving once again that this hormone is responsible for their perception of fear.

Striking similarities

To confirm their results, the scientists conducted a second experiment. During this time, the fish alternately watched videos of their peers in distress or in a neutral state. Then, after some time, the animals joined their peers in the tank.

After watching the videos, the fish immediately snuggled up to their previously distressed partners and reassured them. It is therefore tempting to think that the biochemical mechanisms responsible for our empathy have similar bases for the transmission of fear in fish.

However, while this species’ behavior mirrors our own, it’s hard to say how similar we really are. More studies need to be done to flesh out these findings.