The dog is more than a tame wolf, a study shows: Even puppies that are hardly used to people understand us intuitively better and are more trusting than wolf cubs who grew up with a lot of human contact. This reflects how the social behavior and inter-species communication skills of our four-legged friends have changed for dealing with us within the scope of domestication, the scientists explain.
They don’t just obey simple commands – dogs can understand human signals in a complex way, as many studies have already documented: They orientate themselves by looks and pointing gestures and can even correctly interpret our facial expressions and mood. This pronounced understanding across species boundaries is an amazing ability that distinguishes “our best friends” towards other animals. But to what extent did the ancestors of the dogs also have this talent? So far it remains unclear to what extent the cognition has changed in the development from the wolf (Canis lupus) to the domestic dog (Canis lupus familiaris) and at what stage of development special behavior patterns become apparent.
To answer this question, researchers around Hannah Salomons from Duke University in Durham studied the behavior of 44 dog and 37 wolf pups. The animals were accustomed to different levels of contact with humans: the wolf pups were hand-fed, slept in the beds of their carers every night and were looked after by them almost around the clock just a few days after they were born. In contrast, the puppies lived alone with their mother and littermates and had very little human contact.
Deep-rooted talent
At the age of 5 to 18 weeks, the researchers then carried out tests with the test animals and analyzed the general behavior of the young animals towards humans. In one experiment, they hid a treat in one of two bowls and then gave the dog or wolf pups a tip that should help them find the food. In some experiments, the researchers pointed in the right direction or looked at the container in which the food was hidden. In another version, they placed a small block of wood next to the correct food jar – a kind of cue the pups had never seen before.
As the scientists report, the basic behavioral analyzes of the test animals initially showed that the puppies spontaneously approached strangers much more socially than the wolf cubs, who are actually more used to humans. “The puppies come running when you enter their enclosure, want to climb on you and lick your face. The wolf pups, on the other hand, tend to run into corners and hide, ”explains Salomons.
In the behavioral experiments, the differences became even clearer: the puppies were able to use the human information much better than the young wolves, the scientists report. The bottom line was that the probability that they reacted correctly was about twice as high as that of the wolf pups of the same age, although they had spent much more time with people. The scientists also observed that when the wolf pups found food in a sealed container, they usually tried to solve the problem themselves. The puppies, on the other hand, spontaneously sought human help: They made eye contact and conveyed the message with their behavior: “Can you help me?”
A product of domestication history
However, this does not mean that dogs are more intelligent than wolves, emphasize the scientists: in tests of other cognitive abilities, such as memory or motor impulse control, the dog and wolf pups proved to be equally clever. The cognitive differences therefore only affect the ability to grasp and use people’s messages. “There are many different ways to be smart. Animals produce intelligence that helps them to be successful in their respective habitat and way of life, ”explains Salomons.
This is exactly what was probably at the beginning of the history of wolf-dog domestication, say the scientists: It seems plausible that at some point in the period 12,000 to 40,000 years ago certain groups of wolves increasingly adapted to humans because they were able to benefit from their leftover food. Individuals who showed less shyness and were able to interpret human behavior particularly well probably had advantages, and thus the corresponding genetic predispositions were passed on intensively. As a result, these behavioral characteristics could have intensified over the generations.
So at some point friendships developed across species boundaries: Canis lupus advanced to the form Canis lupus familiaris, which is still with us today. “Our study shows that the social genius of dogs is a product of domestication,” said senior author Brian Hare of Duke University. In further investigations, they are now planning to sound out to what extent the targeted breeding has further influenced the social skills of the dogs later. In addition, studies of various current wolf populations could shed light on whether there are fundamental differences in behavior among them.
Source: Duke University, technical article: Current Biology, doi: 10.1016 / j.cub.2021.06.051