How Executive Function Defines Thinking Better Than IQ

Former NFL player Max’s life unraveled after retirement. Compulsive gambling, heavy drinking and bar fights landed him in jail. Medical imaging later revealed why: extensive brain trauma had severed critical connections between his frontal lobes and the rest of his brain.

Max was one of a dozen NFL retirees studied by neuroscientists using diffusion tensor imaging, a technique that maps white matter pathways. British-Canadian researcher Adrian Owen, who led the study, compared Max’s brain to a computer with isolated components. “His frontal lobes had become almost disconnected,” Owen said. “He couldn’t control many of his thoughts. A major part of his executive function was broken.”

Owen explores these findings in his new book, *Think Before You Think: Understanding and Mastering Executive Function*. Executive function refers to the brain’s ability to regulate attention, planning, memory and emotional responses. Unlike automatic reactions—such as flinching when punched—executive function involves deliberate control over actions and decisions.

Owen, who directs a cognitive neuroscience lab at Western University in Ontario, argues that executive function is a more accurate measure of mental capacity than IQ. While IQ tests attempt to reduce cognition to a single score, executive function consists of multiple, independent processes—much like physical fitness, which cannot be captured by one metric.

“You can’t reduce cognitive abilities to a single number any more than you can reduce physical fitness to one score,” Owen said. “Some people may excel in planning but struggle with memory, while others show the opposite pattern.”

The book challenges conventional views of intelligence. Owen disputes the idea that IQ reflects a singular “intelligence.” Instead, he highlights the role of the frontal lobes in regulating behavior. Damage to these areas can impair theory of mind—the ability to infer what others are thinking—which Owen classifies as an executive function.

“Understanding what someone else is thinking requires conscious effort,” Owen explained. “You have to decide what they might be thinking, not just react automatically.”

He also critiques the persistence of IQ testing, tracing its origins to outdated Western models of intelligence. His research, which analyzed cognitive data from 44,000 individuals, found no single measure could explain variations in brain function.

Owen advocates for greater awareness of executive function in daily life. He encourages people to pause before acting, consider long-term consequences and recognize when automatic responses—like anger or impulsivity—take over.

Max’s case illustrates the stakes. After his frontal lobes were compromised, he lost the ability to override destructive impulses. For Owen, the lesson is clear: thinking before acting isn’t just a metaphor—it’s a biological necessity.