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Larger animals tend to have larger brains than smaller animals. If you divide the actual brain size of an animal by the size of brain an average animal that si
by LarryMullins 4y ago
Larger animals tend to have larger brains than smaller animals. If you divide the actual brain size of an animal by the size of brain an average animal that size would have, you get the "encephalization quotient". If you rank some common animals by encephalization quotient, most of the resulting order probably isn't surprising to many people:
Human: 7.4 - 7.8
Dolphins: 5.3
Chimps: 2.2 - 2.5
Ravens: 2.49
Dog: 1.2
Cat: 1.0
Some of them are surprising:
Mouse: 0.5
Rat: 0.4
Rats are certainly smarter than mice, so this analysis is obviously limited. Still, it seems to generally give expected results.
https://en.wikipedia.org/wiki/Encephalization_quotient https://en.wikipedia.org/wiki/Encephalization_quotient
- svnt 4y agoVery familiar with EQ. If you read the wiki article you cited, most of it is references to people disputing the relevance of EQ. eg 0 Currently the best predictor for intelligence across all animals is [forebrain]neuron count.[[5]](https://en.m.wikipedia.org/wiki/Encephalization_quotient#cite_note-houzel2017-5 https://en.m.wikipedia.org/wiki/Encephalization_quotient#cit...) 1 In a meta-analysis, Deaner et al. (2007) tested ABS, cortex size, cortex-to-brain ratio, EQ, and corrected relative brain size (cRBS) against global cognitive capacities. They have found that, after normalization, only ABS and neocortex size showed significant correlation to cognitive abilities. 2 The notion that encephalization quotient corresponds to intelligence has been disputed by Roth and Dicke (2012). They consider the absolute [number of cortical neurons] and [neural connections]as better correlates of cognitive ability.[[16]](https://en.m.wikipedia.org/wiki/Encephalization_quotient#cite_note-16 https://en.m.wikipedia.org/wiki/Encephalization_quotient#cit...)
- bilsbie 4y agoDo we know why this is the case? It doesn’t seem like a larger body would need additional brainpower.
- im3w1l 4y agoOne idea I've proposed for this is that is mostly correlation and just a little causation. Like assume going bigger is in an easy to get a little bit smarter, but at a large energy cost. Then EQ measures how willing the animal is to invest in additional smarts. If it's willing to invest energy, then it will also mean that evolution will favor intelligent animals more strongly so it will evolve other ways of becoming smarter than just going bigger. Perhaps more faster or more efficient neurons or better mactro structure. And those other things are where the major benefits come from.
- bryanrasmussen 4y agowell a bigger brain requires a bigger head requires a bigger body to carry it, so this would seem to push the chances of higher intelligence onto the animals with the bigger bodies. But I'd guess it is just a slight increase in the likelihood, since the structure is probably of more importance.
- nomel 4y agoIf you assume some sensor density, along the body, is required, then a larger body means more sensory cells, which necessitates more nerves, which requires more neurons to make sense of them in a meaningful way.
- 29athrowaway 4y agoNFT buyers: 0.001