Brief review of fluid reasoning: Conceptualization, neurobasis, and applications

In the early part of the twentieth century the value of nonverbal tests was initially recognized by Yoakum and Yerkes when they wrote how examinees could fail a verbal test of general ability because of limited skills in English. When these examinees were then tested with a nonverbal test of ability, they often performed well, and therefore this approach avoided "injustice by reason of relative unfamiliarity with English." Measuring cognitive ability with nonverbal measures that do not require verbal skills has been supported now for nearly a century. Research has demonstrated that a person's general ability can be measured validly and reliably without requiring the student to read, write, or speak. The neuroanatomical and neuro-anatomical basis for FR is well established and focuses on the frontal-parietal system, and the use of FR measures is a common practice. In this brief article the current conceptualization of Fluid Reasoning (FR) is examined, I suggest how popular used constructs on other common cognitive tests can be conceptualized as a variant of FR. Then, the general neuroanatomical substrates and networks are revisited, followed by summarizing some of the practical scenarios for measuring FR may be useful.