Comparison

To compare is to bring two or more things together (physically or in contemplation) and to examine them systematically, identifying similarities and differences among them. Comparison has a different meaning within each framework of study. Any exploration of the similarities or differences of two or more units is a comparison. In the most limited sense, it consists of comparing two units isolated from each other.

To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and the arts.

General usage

Comparison is a natural activity, which even animals engage in when deciding, for example, which potential food to eat. Humans similarly have always engaged in comparison when hunting or foraging for food. This behavior carries over into activities like shopping for food, clothes, and other items, choosing which job to apply for or which job to take from multiple offers, or choosing which applicants to hire for employment. In commerce, people often engage in comparison shopping: attempting to get the best deal for a product by comparing the qualities of different available versions of that product and attempting to determine which one maximizes the return on the money spent. In the twenty-first century, as shopping has increasingly been done on the internet, comparison shopping websites have developed to aid shoppers in making such determinations. When consumers and others invest excessive thought into making comparisons, this can result in the problem of analysis paralysis.

Humans also tend to compare themselves and their belongings with others, an activity also observed in some animals. Children begin developing the ability to compare themselves to others in elementary school. In adults, this can lead to unhappiness when a person compares things that they have to things they perceived as superior and unobtainable that others have. Some marketing relies on making such comparisons to entice people to purchase things so they compare more favorably with people who have these things. Social comparison theory, initially proposed by social psychologist Leon Festinger in 1954, centers on the belief that there is a drive within individuals to gain accurate self-evaluations. The theory explains how individuals evaluate their own opinions and abilities by comparing themselves to others to reduce uncertainty in these domains, and learn how to define the self. Following the initial theory, research began to focus on social comparison as a way of self-enhancement, introducing the concepts of downward and upward comparisons and expanding the motivations of social comparisons.

Human language has evolved to suit this practice by facilitating grammatical comparison, with comparative forms enabling a person to describe a thing as having more or less of a characteristic than another thing, or to describe a thing in a group as having the most or least of that characteristic relative to the group. The grammatical category associated with the comparison of adjectives and adverbs is degree of comparison.