Research has found the earliest ‘protodogs’ actually had larger brains than their wolf relatives, probably a result of adapting to living alongside us, but by 5,000 years ago, that increase had reversed dramatically, and dogs’ brains were now 46% smaller than wolves’.
https://www.theguardian.com/science/2026/apr/29/dogs-brains-shrink-5000-years-ago
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It has long been known that dogs have less between their ears than wolves, but now research has suggested their brains started to get smaller at least 5,000 years ago.
Experts say the results offer fresh insights into the domestication of our canine companions. However, the findings are unlikely to explain why your spaniel will only drink from a muddy puddle: the researchers say a reduction in brain size does not mean dogs are dafter than their wolf-like ancestors
“The way our dogs live nowadays doesn’t give them the opportunity to always express most of their intelligence,” said Dr Thomas Cucchi, first author of the study from the French National Centre for Scientific Research.
“But they are extremely clever and domestication didn’t make them stupid, but made them really capable of reading us and communicating with us.”
The relationship between humans and canines is ancient, with research revealing the oldest direct genetic evidence for domestic dogs dates back more than 15,000 years.
But while a reduction in brain size is typically considered a hallmark of domestication, there has long been debate over exactly when dogs ended up with smaller brains than wolves, with some experts suggesting this may have occurred early in the dog-human relationship.
However, others argue smaller brain size is not a hallmark of domestication but instead reflects the emergence of pedigree breeds in the last 200 years
https://royalsocietypublishing.org/rsos/article/13/4/252453/481514/Brain-size-reduction-in-dogs-was-already
A Chihuahua will naturally have a smaller brain than a French Mastiff. Did they control for size?
Ma fille a un bichon malté, le cerveau est très très petit, mais c’est le premier chien que je trouve aussi futé. La taille n’est pas essentielle, surtout quand on ne l’utilise pas assez.
I think they’re probably averaging out all canine intelligence, it’s obvious some dogs are smarter than other breeds. I had a vicious chihuahua who would attack you if you wore a hat for example, because he’s like who is this intruder. But then I have a poodle mutt and she’s clearly intelligent she knows 10 different tricks including playing games of fetch with herself running up hills and chasing the ball, she also catches rabbits and lizards.
I remember reading that dogs might have had a genetic mutation similar to Williams–Beuren syndrome in humans that made them hypersocial.
what size are they now? is it still 46% smaller?
I can’t help but wonder if this a prelude of what will happen to the human brain after generations of living alongside AI.
Well yeah. It’s a big brain move to ally with humans and get your needs taken care of. And when all your needs are taken care of you no longer need such a big brain.
Has size of brain been proven to differences in intelligence? Any other proven differences?
>and dogs’ brains were now 46% smaller than wolves’.
It seems to be, that the size of the brain is not much important for intelligence.
P.S. Also, now we know, that the dogs were the first domestic animals ever. They were domesticated 15000 years ago.
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Does a bigger brain equate to a smarter dog (or wolf)? What accounts for the larger size?
I just imagine ancient dog breeders being like; this was a mistake making them smarter, we have to go back!
Step one, trick the humans into giving us food. Step two, my bloodline can chill forever.