We dismiss animals as having little or no intelligence or self- awareness but scientists are learning this is not universally true, writes WILLIAM REVILLE
SCIENCE is only beginning to understand the inner lives of non-human animals but the information gleaned so far is fascinating. Not only are some animal species unexpectedly clever, but they also show other mental complexity that resembles the inner lives of humans, raising serious questions about how we treat animals. Recent research in this area was summarised by Jeffrey Kluger in Timemagazine on August 16th.
Traditionally humans felt they had a free hand regarding how they treated animals. For a start, the Bible grants humans “dominion over the beasts of the field”. And then animals seemed qualitatively vastly inferior to humans. Animals didn’t use tools or language as humans do. Animals didn’t suffer like humans, unable to grieve or fearfully (or joyously) anticipate the future or regret the past. Animals couldn’t empathise, or ponder their own mortality.
Humans are undoubtedly unique and “special”, but, research has now qualified many human/animal distinctions, at least in certain cases. Take language, for example. Although animal vocal chords cannot articulate words as those of humans do, there are several examples of apes successfully learning rudimentary language. Kluger describes Kanzi, an ape at a research centre in Iowa, who can talk to you by pointing at words on a plastic sheet. Kanzi knows 384 words and uses them appropriately. For example, after seeing flooding, Kanzi spontaneously described it by sequentially picking the words “big” and “water” from his list of words.
Several animal species use tools, the most proficient being the corvids, a family of birds that includes crows, ravens, rooks, magpies, etc. Crows will bend a wire to make a hook to fish food out of a plastic tube. And, recently, a raven was observed dropping stones into a pitcher of water to raise the water enough (Archimedes Principle) to allow the bird to drink. See the Huffington Post's clever crows at http://url.ie/7cl1 and Wired's rooks at http://url.ie/7cl4 for some amazing video footage.
A bird’s brain is a so small that the term “bird brain” is used to express derision and, to compound matters, the bird brain has no cortex, which is the corrugated outer layer of the mammalian brain where cognitive functions reside. Apparently, the bird is able to use the basal ganglia, a primitive brain structure also present in mammals, in a very efficient manner. The birds also live in complex bird societies with stable group bonds. This co-operative living seems to boost intelligence. On the other hand, animals such as cattle that live in herds, with little social structure, show very limited intelligence.
Generosity has been demonstrated in Capuchin monkeys where a monkey, given a choice between two tokens, one releasing two slices of apple for himself and the other releasing one slice each for himself and another monkey, prefers the latter option when the other monkey is a companion. This is believed to arise from the sense of pleasure experienced in giving – reward centres in the human brain become active when the subject donates to charity.
Can animals feel love, hope, grief, etc? Elephants and apes appear to mourn their dead, remaining with a dead companion’s body for days. And we all know the story of Greyfriars Bobby, the little dog in Edinburgh who loved and missed his dead master so much that he spent the remainder of his life sitting on his master’s grave.
How aware are animals that they exist as separate entities from other animals?
The standard test here is whether an animal can recognise its reflection in a mirror for what it is. For example, a dog thinks his reflection is another dog. Only a few species pass the mirror test, including apes, dolphins and elephants. If you apply a daub of paint to one of these animals and show them their reflection in a mirror, apes and elephants will touch the paint daub with their finger or trunk, rather than touch the reflection.
Dolphins manoeuvre their position to see the reflection better.
Smartness is approximately proportional to the ratio of brain weight to body weight but only a rough hierarchy of animal brain power can presently be constructed.
The smartest non-human animals include the great apes and the cetaceans (whales, dolphins, porpoises, etc), animals with big brains that live in complex societies; next come the tool-using corvids (crows, ravens, magpies, etc), with their strong social ties; next are the social carnivores that hunt co-operatively, eg lions, hyenas, etc; then herd animals such as cows; and at the bottom are animals like bivalves (cockles, mussels, oysters, etc) that show little evidence of anything beyond automatic behaviour and are probably not even conscious.
This new understanding of animals’ inner lives calls on us to show many animals much more respect than they currently receive.
At a minimum, factory farming in poor conditions of animals above the level of bivalves, and using them to test cosmetics, seems unjustifiable. And reflection on our new knowledge should surely motivate us to go far beyond such minimal measures.
William Reville is UCC’s professor of biochemistry and public awareness of science officer –http: //understandingscience.ucc.ie