How large is a cat's brain?
Cat intelligence
0.91%[3] of its total body mass
The brain of the domesticated cat is about five centimetres (2.0in) long, and weighs 25–30g (0.88–1.06oz).[1][2] If a typical cat is taken to be 60cm (24in) long with a weight of 3.3kg (7.3lb), then the brain would be at 0.91%[3] of its total body mass, compared to 2.33%[3] of total body mass in the average human. Within the encephalization quotient proposed by Jerison in 1973,[3][4] values above 1 are classified big brained, while values lower than 1 are small brained.[5] The domestic cat is attributed a value of between 1–1.71 relative to human value that is 7.44–7.8.[1][3] The largest brains in the Felidae family are those of the tigers in Java and Bali, of which the largest relative brain size within the panthera is the tigris.[6] It is debated whether there exists a causal relationship between brain size and intelligence in vertebrates. Correlations have been shown between these factors in a number of experiments. However, correlation does not imply causation. Most experiments involving the relevance of brain size to intelligence hinge on the assumption that complex behavior requires a complex (and therefore intelligent) brain; however, this connection has not been consistently demonstrated.[7][8][9][10][11]