We all know that dog years aren't really the same as human years. We've all heard that one dog year is equivalent to seven human years, but this isn't actually accurate. It's true that dogs age more quickly, but each dog year doesn't equal seven human years. Aging in dogs slows down when they reach adulthood, and not all dogs age at the same rate.
Thus, we've been hearing a myth for a long time. However, it still makes sense to ask—does one human year feel like multiple years to dogs?
It's likely that the answer is yes. A study has found that body mass and metabolic rate determine how different animals experience time. Smaller animals actually experience time as if the world were in slow motion. Thus, smaller animals are able to take in more information than animals bigger than they are.
Pretend that you have the ability to dodge bullets. A bad guy stands in front of you and shoots at you. You see the bullet leave the gun and watch it soar towards you. You step aside as it coasts closer. The bullet glides past you and hits the wall behind you instead of your chest. That's kind of how lighter and smaller animals with fast metabolisms perceive the world.
Animals perceive the passage of time based on how quickly their nervous system processes information. This is an important survival tool that can spell the difference between life and death. After all, if you meet a predator that moves fast, you'll have a better chance of escaping if you can process more information in an instant.
A team of researchers showed animals a quickly flashing light to test how they perceive time. Interestingly, if the flashing is quick enough, some animals and we humans as well will perceive that the light isn't flashing. In other words, we'd see it as just a continuous, unblinking light. Researchers tested the highest frequency at which the animals can perceive the flashing by analyzing the animals' behavior or brain activity. They found that things unfold more slowly to animals that can still perceive the flashing of the light at higher frequencies.
Dog years, bird years, lizard years—these are all different from the way we humans perceive time. Bigger animals aren't able to perceive as many things as smaller animals, likely because it would be a waste of energy for them. For example, a bird of prey like a hawk or an eagle would definitely benefit from perceiving time more slowly. However, large animals like elephants or whales don't need this same ability. It all boils down to how these different nervous systems and physiology interact with the animal's environment to conserve energy.
The researchers say that though their study focused on vertebrates, they also studied other animals like flies and deep-sea creatures. Flies, for example, are four times faster on the uptake than humans. No word on how dogs specifically perceive time, but we can assume that dog years are somewhat richer in information than human years.
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