often gets a bad press, including the apparently unfounded assertion that breeding for looks has an adverse effect on intelligence. But has anyone ever bred dogs, or any other species, purely for intelligence? Just how intelligent could any species get through selective breeding? And how quickly?
鈥� Intensive breeding for looks in any animal adversely affects intelligence and every other attribute 鈥� eventually including those very looks. This is intrinsic to selection, whether natural or artificial.
The effectiveness of selection depends on the range of relevant genes in the population: the larger the natural population, the greater the range of genes is likely to be. Selection for any desired attribute rapidly reduces that range: in a single generation, less than 1 per cent of a population might be selected, immediately reducing the range of 鈥渋rrelevant鈥� genes, including genes for mental or physical health or functionality.
Advertisement
Dogs bred for show are commonly selected so obsessively that any harmful genes they carry become fixed in their populations. In competitive show breeding, selection is particularly stringent, with the result that gene pools shrink rapidly. Most mutations and recessive genes in small, closed populations are harmful, so progress is overwhelmingly negative.
The closest we come to breeding for intelligence and functionality in dogs is in certain working breeds. Breeding companion animals specifically for desirable behaviour, intelligence and health should be gratifying, but it is also challenging and commercially precarious. People who need companions prefer to buy mongrels.
Jon Richfield, Somerset West, South Africa
鈥� Asking if anyone has bred a variety of dog purely for intelligence begs the question of what is meant by intelligence. The psychologist Robert Sternberg has shown that what we think of as 鈥渋ntelligent鈥� depends on what we value 鈥� specifically what we think people should be good at. So what we consider to be a clever dog would be one that does a good job at what we want it to do: herd sheep well or guard the house effectively. We have no need for dogs that are adept at calculus or playing the futures market, so we have never tested our capacity to breed this into them.
Sternberg identified three signs of intelligence: the ability to adapt to environments, the ability to shape environments and the ability to understand that the environment is not optimal, thus facilitating a move to a more congenial niche. On this basis, you could make the argument that almost all species are intelligent, even bacteria, because at the very least they are adapted to their environments. In addition, many can up sticks when things are not so good and move elsewhere, and some can even shape their environment in some way congenial to them.
Maybe dogs deserve special mention because they have shaped their environment by making themselves useful and appealing to humans, in return for food and shelter.
Catherine Scott, Surrey Hills, Victoria, Australia