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.
Manot 1
Manot 1 is an adult individual represented by an almost complete skullcap (calvaria) very similar to those of modern humans. But it has a relatively small brain size, which is estimated at around 1,100 mL, compared to modern human brain which is about 1,400 mL. Its unique features are the bun-shaped occipital, the moderate arch of the parietals, flat sagittal area, presence of a suprainiac fossa, and the pronounced superior nuchal line. These combined features indicate that it shares a number of features between the most recent African humans and those of European from the Upper Paleolithic period. But it has notable differences from those of other archaic humans found in the neighbouring Levant. The discoverers concluded that: