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.
Jungle cat
The jungle cat is a medium-sized, long-legged cat, and the largest of the extant "Felis" species. The head-and-body length is typically between . This cat stands nearly at shoulder and weighs . Its body size decreases from west (Israel) to east (India); this was attributed to greater competition from small cats in the east; body size shows a similar decrease from the northern latitudes toward the tropics. Sexually dimorphic, females tend to be smaller and lighter than males. The face is long and narrow, with a white muzzle. The large, pointed ears, in length and reddish brown on the back, are set close together; a small tuft of black hairs, nearly long, emerges from the tip of both ears. The eyes have yellow irides and elliptical pupils; white lines can be seen around the eye. Dark lines run from the corner of the eyes down the sides of the nose and a dark patch marks the nose. The skull is fairly broad in the region of the zygomatic arch; hence the head of this cat appears relatively rounder.