No. Large differences in brain weight (e.g. factors of 10 or more) can sometimes matter. But weight is just a poor proxy for more important factors: Number of n

No. Large differences in brain weight (e.g. factors of 10 or more) can sometimes matter. But weight is just a poor proxy for more important factors: Number of neurons, number of neuronal interconnections, and specialization of brain areas. Within a species, brain weight differences are unimportant. Even between species it's often unimportant. Blue whale brains are 4x as heavy as human brains but the whales have fewer neurons, and most of those neurons are dedicated to audio processing. https://blogs.scientificamerican.com/news-blog/are-whales-smarter-than-we-are/ https://blogs.scientificamerican.com/news-blog/are-whales-sm...