fallacy of composition

The fallacy of composition is an error in logic where one incorrectly assumes that what is true for each individual part of a whole must also be true for the whole itself. This type of erroneous reasoning has the appearance of being sound but is flawed.12

For example, if each component of a machine is lightweight, it doesn't automatically mean the entire machine will be lightweight. Similarly, if an individual's increased income leads to greater purchasing power, it doesn't follow that a general increase in income for everyone would lead to the same benefit if prices also rise proportionally. This fallacy can arise from an improper use of words, specifically when the distributive use of a term (referring to individual members of a group) is confused with its collective use (referring to the group as a single unit).12