General factors are found in the measurement of many human traits. The concept of dominant general factors (DGFs) is introduced to represent the magnitude of general factors within numerous content domains. DGFs are defined as coming from the largest sources of reliable variance and influencing every variable measuring the construct. Although these factors are most frequently found in measures of cognitive ability, they are not limited to cognitive abilities. Examples are provided for a variety of construct and content domains along with estimates of their DGF percentages, ranging from 38% to 92%. Several reasons for these results are offered, and a call for concerted research is made. Research that ignores DGFs by treating specific factors or constructs within a domain as if they were distinct and uncorrelated can lead to errors in interpretation.