Dogs vs. Wolves: Critical Period of Socialization Explains Behavioral Differences
Dogs and wolves are actually from the same species: Canis lupis. Physically and genetically, these two canines are similar, but behaviorally, it has been difficult for biologists to understand why wolves remain fiercely wild, while dogs are content on being man's companion. While domestication of the dog plays a huge role in the differences between the two, according to new research, evolutionary biologist Kathryn Lord at the University of Massachusetts Amherst suggests the different behaviors are related to the animals' earliest sensory experiences and the critical period of socialization.
After observing responses of seven wolf pups and 43 dog pups to familiar and novel smells, sounds, and sights from 2-7 weeks old, researchers confirmed that both wolf pups and dogs develop senses at the same time: smell at two weeks, hearing at four weeks and vision by six weeks on average.
However, what varies between these pups is the four-week developmental window called the "critical period of socialization." Socialization is the process in which animals learn to recognize and interact with other species in their environment. Wild wolf pups will begin to explore at two weeks old, when they are still blind and deaf, and must rely primarily on their sense of smell, whereas dogs begin this period at four weeks.
When the socialization window is open, wolf and dog pups begin walking and exploring without fear and will retain familiarity throughout their lives with those things they contact. But as the period advances, fear will increase and after the socialization window closes, new sights, sounds and smells will elicit a fear response.
Because each subspecies experiences the world with different senses, this period is extremely different, and likely leads to different developmental paths, says Lord.
Lord is the first to report that wolf pups are still blind and deaf when they begin to walk and explore their environment. She also notes: "When wolf pups first start to hear, they are frightened of the new sounds initially, and when they first start to see they are also initially afraid of new visual stimuli. As each sense engages, wolf pups experience a new round of sensory shocks that dog puppies do not."
These findings lead to an alternative explanation for the difference in dogs' and wolves' abilities to form interspecies social attachments, such as those with humans, Lord says. This new information has implications for managing wild and captive wolf populations, she says.
The findings can be found in the current issue of Ethology.
Read more at UMass Amherst.
Wolf pup image via Shutterstock.