Flynn discovered an upward trend around the world, and Spearman measured it with a g factor.  
The BITCH test was designed to measure an often overlooked aspect of this trait.  Raven's Progressive Matrices are used to measure this, as is a scale named for Wechsler.  Robert Sternberg proposed a triarchic model of this trait, and Arthur Jenson believes it to be strongly hereditarian.  Cattel and Horn divided in into fluid and crystalline forms, while Howard Gardner developed a theory of multiples types of this, such as bodily-kinesthetic. Flynn discovered an upward trend around the world, and Spearman measured it with a g factor.  Binet and Simon developed a test to measure, for 10 points, what trait controversially discussed in The Bell Curve and associated with high IQ scores?
The BITCH test was designed to measure an often overlooked aspect of this trait.  
{Intelligence} [accept equivalents, accept {IQ} until end]