encephalization quotient n. Quick reference
A Dictionary of Psychology (4 ed.)
... quotient n. An index of the comparative intelligence of animal species formulated by the Polish-born US psychologist Harry Jacob Jerison (born 1925 ): brain volume of the animal in question divided by brain volume of a standard comparison animal belonging to the same class, correcting for body size. If a cat is arbitrarily assigned a standard mammalian encephalization quotient of 1.0, then a rat scores 0.4, a chimpanzee 2.5, a dolphin 6.0, and a human 6.3. Compare A/S ratio , progression index . EQ abbrev. [From Greek en in + ...
encephalization quotient Quick reference
A Dictionary of Biology (8 ed.)
...encephalization quotient ( EQ ) A measure of the relative size of the brain of a particular species compared with the expected value for members of the group to which it belongs. It is used to estimate the comparative intelligence of animals, particularly in anthropology. A logarithmic plot of brain mass against body mass for numerous representative species has a slope of roughly 3/4, which provides the baseline for calculating EQ values. The EQ corresponds to the distance above or below this line, and an EQ of 1 equates to the brain mass expected for the...
encephalization quotient
progression index
A/S ratio
intelligence
progression index n. Quick reference
A Dictionary of Psychology (4 ed.)
...n . An index of the comparative intelligence of mammalian species, based on a modification of the encephalization quotient, defined as volume of neocortex in the animal in question divided by volume of neocortex in a standard comparison animal belonging to the same order, correcting for body size. If a chimpanzee is arbitrarily assigned a standard progression index for primates of 1.0, then humans score 3.2. Compare A/S ratio , encephalization quotient...
A/S ratio abbrev. Quick reference
A Dictionary of Psychology (4 ed.)
...an index of the comparative intelligence of mammalian species formulated by the Canadian psychologist Donald O(lding) Hebb ( 1904–85 ), defined as brain volume devoted to association areas divided by brain volume devoted to sensory and motor areas. Compare encephalization quotient , progression index...
intelligence n. Quick reference
A Dictionary of Psychology (4 ed.)
...practical intelligence; but during the 1990s some authorities began to consider emotional intelligence as another form of intelligence. The standard index of intelligence is the IQ score. See also A/S ratio , crystallized intelligence , emotional intelligence , encephalization quotient , fluid intelligence , g , Guilford's cube , inspection time , intellectual disability , intelligence test , multiple intelligences , nerve conduction velocity , n 140, primary mental abilities , processing speed , progression index , p 200 , social...
Brain Size Evolution Reference library
Encyclopedia of Evolution
...larger-bodied primates have greaterabsolute cranial capacities than smaller species, their relativebrain sizes (the ratio of brain size to body size) are smallerbecause of allometric scaling.Courtesy of Dean Falk. To incorporate the brain–body size allometries, Encephalization Quotients ( EQ ) are often used instead of absolute brain size or brain/body ratios. EQs indicate the relationship between a particular brain size and the brain size expected of a model animal of the same body size given a particular allometric relationship. Departures from the...
The Social Brain Hypothesis and Human Evolution Reference library
Robin I. M. Dunbar
The Oxford Encyclopedia of Social Psychology
...in a new domain. Concepts in Neuroscience , 1 , 27–51. Bruner, E. (2010). Morphological differences in the parietal lobes within the human genus: A neurofunctional perspective. Current Anthropology , 51 , S77–S88. Bruner, E. , Manzi, G. , & Arsuaga, J. L. (2003). Encephalization and allometric trajectories in the genus Homo : Evidence from the Neandertal and modern lineages. Proceedings of the National Academy of Sciences , USA , 100 , 15335–15340. Burki, F. & Kaessmann, H. (2004). Birth and adaptive evolution of a hominoid gene that supports...
