David Barash discusses the move towards recognition of cognition in animal minds in this Psychology Today article.
David P. Barash Ph.D.
How Ethologists Learned to Respect Animal Minds
Animals think; here's how even the experts came to agree.
How did the erroneous view that other animals lack an internal mental life get started? It wasn’t merely a consequence of self-serving theology and a reaction to anthropomorphism, but has some legitimate basis in science. Early research by ethologists focused on the role of “releasers,” simple stimuli that are typically present in members of a given species, to which individuals respond automatically and instinctively—nearly always without any indication of insight.
The classic example was the orange spot near the tip of an adult herring gull’s bill. Niko Tinbergen (who shared a Nobel Prize for his ground-breaking research) found that herring gull chicks instinctively pecked at this spot, presented by a parent gull, who then responded—also instinctively—by regurgitating a semi-digested fish meal into the mouth of the hungry chick. Especially noteworthy is that chicks were equally likely to peck at something that at least to the human observer doesn’t look at all like the head of a herring gull, namely a tongue depressor or popsicle stick on which an orange dot has been painted.
Tinbergen also noticed that male stickleback fish, kept in his lab at Oxford, used to rush to the side of their aquarium and display aggressively when mail trucks—painted red in England at the time—drove by. Not coincidentally, male sticklebacks develop bright red chests when in breeding condition, and their cognitive skills are so limited (or more accurately, in this case, bypassed by a simple algorithm) that they take anything moving and bright red as a signal that automatically releases aggressive territorial defense. In my own research, I have taken advantage of a similar releaser among male mountain bluebirds, whose bright blue plumage can be mimicked by a bright blue racket-ball, to the extent that the ball, impaled on a nearby tree, evokes a full repertoire of mountain bluebird display behavior. Such examples are common currency among students of animal behavior.
Further evidence for the cognitive limitations of many animals comes from the existence of “supernormal releasers,” created when researchers take a releaser and enhance or exaggerate it to supernormal proportions, whereupon it evokes a supernormal response, demonstrating once more—often to comical excess—an absence of deep thought (or even shallow thought) among a wide range of animals. A notable example is provided by Pacific oystercatchers, rather debonair looking shorebirds with black and white plumage, and bright orange legs and beak. These crow-sized birds lay eggs that are lightly speckled and appropriate for their mass—a bit smaller than hen’s eggs—which they incubate.
Take a watermelon, however, and paint it with similar speckling, and the seemingly addle-pated oystercatcher will abandon her own eggs and perch, apparently quite satisfied, albeit looking entirely absurd to a human observer, atop this super-normal releaser (which might weigh 20 times her body mass and could never have been laid by the animal in question), all the while ignoring her own eggs.
Read the entire article hhttps://www.psychologytoday.com/us/blog/peace-and-war/201911/how-ethologists-learned-respect-animal-mindsere.