There is no way to measure the IQ of a cat, and therefore no way to talk about the average IQ of a cat. IQ tests are standardized and based on research that simply doesn’t exist for animals. While cats are highly intelligent, we may never know the full extent of their cognitive abilities. The brain of a domesticated cat is about five centimeters long and weighs 25-30 grams, which is about 0.91% of its total body mass. Within the encephalization quotient proposed by Jerison in 1973, the domestic cat is attributed a value of between 1-1.71, while human values range between 7.44-7.8. However, it is important to note that cat intelligence study is mostly from consideration of the domesticated cat, and the process of domestication has allowed for closer observation of cat behavior and in the increased incidence of interspecies communication, and the inherent plasticity of the cats brain has become apparent as the number of studies in this have increased scientific insight.