IQ is one of the most-studied traits in brain imaging studies. And yet it has a weaker relationship with brain structure and function in children than socioeconomic status does, according to a study published today in Science. The apparent link between IQ and brain differences largely disappears once socioeconomic status is controlled for, the findings suggest. The results point to the importance of factoring in socioeconomic status in analyses of brain imaging datasets, the researchers say.