There has been little scientific evidence that reptiles experience good moods — until now. Researchers in the UK identified what they describe as “mood states” in red-footed tortoises by administering tests that use responses to ambiguity as windows into the psyche. The results, published in Animal Cognition, could apply to many more reptiles and have profound implications for how people treat them.
Reptiles have a long-standing reputation as being unintelligent. Writing in 1892, Charles Henry Turner, the pioneering comparative psychologist, described reptiles as “intellectual dwarfs”. Eight decades later, in 1973, prominent scientists were referring to them as “reflex machines” and as possessing “a very small brain”.
Oliver Burman, who studies animal behaviour at the University of Lincoln in the UK and is an author of the paper, is among the scientists responsible for what some have called a “reptilian renaissance”. An array of findings — tortoises learning from one another, snakes with social networks, crocodiles displaying complex communication — indicate that reptiles are no less brainy than mammals and birds.
But do they have moods? Burman and his colleagues approached that question using a cognitive bias test. This operates on a principle common to many animal minds, human and non-human alike: individuals in a good mood are more optimistic about uncertain outcomes, whereas those in a bad mood tend to be pessimistic.
“These results significantly extend contemporary knowledge of the capacity for reptiles to experience mood states,” the paper noted. The results echoed those of a similarly designed 2010 study on dogs with separation anxiety.
How broadly can the new findings be extrapolated to other reptiles? “We can’t say for sure,” said Anna Wilkinson, a reptile cognition specialist at the University of Lincoln and an author of the study. “We need to test other groups of reptiles.”
On a Facebook group devoted to reptiles and amphibians, some members remarked that scientists had merely discovered what reptile owners already knew. But Gordon Burghardt — a comparative psychologist at the University of Tennessee, Knoxville, US, and pioneer in the study of reptile intelligence who was not involved in the study — noted the value of empirical demonstration. Asked whether he thought that many and perhaps even all reptiles experienced moods, Burghardt replied, “Certainly.”
For Burman and Wilkinson, the most important implication of their finding was the urgency it gave to understanding the welfare of captive reptiles. Snakes in particular are commonly kept in too-small enclosures with little enrichment. In future research, Wilkinson said, “what we would love to do is to look at what happens if you give a snake a playground.”
NYTNS