Dinosaurs were the first to understand other people’s vision, study suggests

Understanding that others have different viewpoints than you is essential to human society. Accepting another person’s point of view is a complex skill that emerges by age 2. A new study from Lund University in Sweden has been published Scientific advances, suggesting that this ability first arose in dinosaurs, at least 60 million years before it appeared in mammals. These findings challenge the idea that mammals evolved novel and superior forms of intelligence in the wake of the dinosaur extinction.

If someone near you turns their head towards something in the environment, you can’t help but follow the direction of their gaze. This reaction is also observed in mammals, birds and reptiles. This is a great way to gather information about what caught your colleague’s attention that you might otherwise have missed.

However, following someone’s gaze from your gaze to an area that was initially restricted is a more advanced behavior. By repositioning yourself to see what the other person sees, you will understand that the other person has a different perspective. This ability, called „visual perspective taking,” develops in children between 1.5 and 2 years of age and serves as a foundation for later understanding of referential relationships and that other people have different minds from you.

Visual perspective taking has, to date, been observed in only a few species. Mainly in monkeys and a few monkeys, but also in dogs and crows. However, there is limited knowledge about the evolutionary origins of this important social skill. A team of researchers from Lund University aimed to investigate the early origins of visual perception in dinosaurs.

By comparing crocodiles to more ancient birds called palaeognaths, they found that visual vision evolved in the dinosaur lineage 60 million years or so before it appeared in mammals.

The closest relatives of birds are crocodiles. Their neurology has remained unchanged for hundreds of millions of years, and is similar to the common ancestor of dinosaurs and crocodiles. Paleognath birds include ostriches such as emus and rheas, but also the flying dynamos. Their brains were comparable to those of their non-avian predecessors, the paravian dinosaurs, including notables such as velociraptors. Comparing these two groups of animals creates a bracket around the extinct lineage of dinosaurs that lead to modern birds.

Crocodiles do not exhibit visual vision, although research has shown that they follow a visible location. In contrast, all bird species tested exhibited visual perspective taking. In addition, birds engage in a behavior called „checking back,” where the observer looks back at the observer’s eyes, and re-tracks the gaze when nothing can be found in the direction of the gaze the first time. This behavior indicates the expectation that gaze represents a target in the environment. Previously, it was found only in humans, monkeys and apes and crows.

Paleognathous birds appeared about 110 million years ago, predating two mammal groups—animals and dogs—by 60 million years. Given the neurological similarities between these avian and non-avian ancestors, it is plausible that this ability appeared earlier in the dinosaur lineage. However, this is less likely to have been the case in early dinosaurs with more crocodile-like brains.

Perhaps future research will show the ability to be more widespread among mammals than currently known, but even so it predates dinosaur origins. Nevertheless, it is not surprising that visual perception arose in dinosaurs, including birds, for their superior vision compared to most mammals that historically relied on nocturnal adaptations. It was only with the appearance of primates and some carnivores that our eyesight improved.

This is another finding that questions the prevailing view that mammals drive the evolution of complex cognition and that they are the cognitive benchmark against which other animals should be compared. A growing body of research is showing remarkable neurocognition in birds, the avian dinosaurs, prompting a rethinking of the natural history of cognition.

Senior author, Prof. Matthias Oswath says, „Early in my career, ravens were nicknamed 'monkeys with feathers’, due to several research findings that revealed their remarkable intelligence, I began to doubt whether this was still appropriate. Fauna should be considered honorary birds.”

The first author (then a Ph.D.-student), Dr. Claudia Zeiträg says, „Birds are generally overlooked for their cognitive abilities. Our findings show that not only do they have many cognitive abilities on par with monkeys, but their ancestors may have had these abilities long before they evolved into mammals.”

The middle writer, Dr. Stefan Reber says, „Crocodiles are excellent models for studying the evolution of cognitive abilities in birds. They most likely shared a common ancestor with dinosaurs and crocodiles. If crocodiles lacked bird ability, it may have evolved in the dinosaur lineage after the split. This approach allows us to study the cognition of extinct species.”