Cat intelligence
The brain of the domesticated cat is about long, and weighs . If a typical cat is taken to be long with a weight of , then the brain would be at 0.91% of its total body mass, compared to 2.33% of total body mass in the average human. Within the encephalization quotient proposed by Jerison in 1973, values above 1 are classified big brained, while values lower than 1 are small brained. The domestic cat is attributed a value of between 1–1.71 relative to human value that is 7.44–7.8. 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". 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.
Cat intelligence
Taurine is an amino acid, which is essential in cat diets due to their low capacity to synthesize it. Because taurine has the ability to cross the blood–brain barrier in the brain, it has been found to have a role in many neurological functions, especially in the visual development. Without taurine, felines can have an abnormal morphology in the cerebellum and visual cortex. When cats were fed a diet deficient in taurine, this leads to a decrease in the concentration of taurine in the retina of the eye. This results in deterioration of the photoreceptors, followed by complete blindness.