How Smart are Mice?

Significance

• In general, people define intelligence in such a way that places humans at the top of the list. In reality, and especially when it comes to animals, raw intelligence cannot be measured, largely because intelligence itself is multifaceted. Even in human IQ testing, a variety of abilities are explored to get the best possible picture of a person's potential intelligence. Animals like mice are tested for ability based on criteria that do not discriminate against their physical forms. For example, while primates are tested on their ability to use tools because their bodies are built for the exercise, mice are not, because the use of tools is not possible for them. The testing of mouse intelligence will usually include factors like how quickly they respond to classical and operant conditioning, and how they respond to increasingly complex test patterns.

Size

• The wild ancestors of mus musculus acquired their capacity for learning through the development of survival skills and instincts. Mice in the wild need to be extremely alert, cautious and smart in order to stay alive. Their small size combined with their speed and agility made them prime candidates for increased spatial and problem-solving abilities. Though there is some argument over whether brain size is an accurate measurement of intelligence, if one compares the size of a mouse's brain to the size of its body, the ratio of brain to body weight in mice is nearly identical to that of humans. Even when this concept is remedied for possible inconsistency, mice still rank fairly high.

Features

• Mice can be observed for intelligence through their sociability. Mice become attached to each other, to humans and sometimes other species of animal. They communicate with each other at frequencies too high for the human ear and have been known to vocalize at human-audible levels when interacting with people. They can also communicate through smell and touch, and are able to use these senses to their advantage in their environment. Mice have "guard hairs," which are sensitive hair on their bodies that help them collect information, and use their whiskers for the same purpose.

Types

• Mice can be trained to perform a stunning variety of tasks. Lab scientists have used mice and other rodents for many years as test subjects due to their capacity for learning and responding to stimuli. Mice are tested for spatial awareness using mazes, which also relates to scenting capabilities. They are also tested for problem-solving skills, and are known to perform tasks in groups. Pet mice can be trained in to perform tricks or to do simple everyday tasks like using litter boxes.

Potential

• Due to human interference, mice may become even smarter than they are naturally. Scientists from MIT (Massachusetts Institute of Technology) and the University of Washington have manipulated a gene in mice that affects the way they form associations. The mice in this project, nicknamed "Doogie" mice, have longer memories and are able to make faster conclusions about their environment. For example, the mice can complete a spatial intelligence test twice as fast as normal mice. The Doogie mice also have brains that retain their plasticity as they age, meaning that their brains keep some juvenile features. One psychological downside to this extended brain power is that the longer memories may cause the mice to remember negative events or injuries better, though it is still unclear whether the mice are reacting to memory or are susceptible to chronic pain problems.