A group of Spanish scientists has found that orcas, also known as killer whales, have similar characteristics in common with humans and chimpanzees.

The scientists studied a total of 24 orcas at the SeaWorld Orlando, SeaWorld San Diego and Loro Parque zoos. Six of these orcas come directly from the wild while the rest were born under human observation.

The researchers found that orcas display characteristics like playfulness, joy, independence, stubbornness, courage, sensitivity, protectiveness and kindness - often attributed to primates like humans and chimpanzees.

Scientist Yulan Ubeda from the University of Girona said that the study is the first scientific work that shows the connection between the characteristics of orcas and humans. Ubeda said that the orcas might develop these characteristics in order to live in intimate societies.

The details of the study were published in the Journal of Comparative Psychology.