Introduction
In our increasingly connected world, multitasking has become not just common but celebrated—a supposed skill that allows us to navigate the demands of modern life efficiently. We pride ourselves on our ability to simultaneously respond to emails, participate in video calls, check social media, and complete work tasks. However, Stanford researcher Clifford Nass’s pioneering work challenged this fundamental assumption, suggesting that what we perceive as a productivity enhancement might actually be undermining our cognitive abilities. His blunt assessment—that “multitaskers are terrible at every aspect of multitasking”—represents not just a provocative statement but the conclusion of rigorous scientific investigation into how our brains process information in an age of digital distraction.
The Seminal Study: “Cognitive Control in Media Multitaskers”
In 2009, Nass, along with colleagues Eyal Ophir and Anthony Wagner, published what would become a landmark paper in the Proceedings of the National Academy of Sciences. Their research approach was elegantly designed to test whether habitual media multitasking correlates with differences in cognitive processing abilities.
The researchers developed a Media Multitasking Index (MMI) to identify participants who were either heavy media multitaskers (HMMs) or light media multitaskers (LMMs). They then subjected both groups to a series of cognitive tests measuring three critical aspects of information processing: filtering (the ability to ignore irrelevant information), working memory management, and task switching.
Contrary to the researchers’ initial expectations, heavy multitaskers performed significantly worse on all three dimensions. They were more easily distracted by irrelevant stimuli, less effective at keeping information organized in working memory, and—perhaps most surprisingly—worse at switching between tasks, despite having more practice with task-switching in their daily lives.
The Breadth-Biased Attention Theory
Nass’s research suggested that heavy multitaskers develop what he called a “breadth-biased” approach to attention. Rather than deeply focusing on relevant information and filtering out distractions, habitual multitaskers tend to pay attention to a wider array of stimuli, but with less depth. They become, in Nass’s words, “suckers for irrelevancy”—unable to distinguish between important and unimportant information.
This breadth-biased attention appears to be a fundamental shift in information processing strategy. While it might seem advantageous to monitor multiple information streams, the research revealed that this comes at a significant cost to cognitive efficiency. The multitasker’s brain is constantly dividing resources, never fully engaging with any single task.
Subsequent Research and Debates
In the years following Nass’s groundbreaking work, numerous researchers have explored the relationship between media multitasking and cognitive control. A 2021 meta-analysis examined a decade of research since the original paper, analyzing 118 assessments across various studies. While this analysis confirmed a small but significant association between media multitasking and decreased cognitive performance, it also revealed considerable heterogeneity in results across different studies and methodologies.
Some researchers have reported that multitasking is associated with decreased academic performance, reduced ability to concentrate, and even structural differences in brain regions associated with cognitive control. Others have found more nuanced relationships or conditional effects depending on the specific tasks involved.
These varied findings suggest that the relationship between media multitasking and cognitive control is complex and likely influenced by multiple factors, including individual differences, task demands, and measurement approaches. The research community continues to investigate these complexities, building upon Nass’s foundational work.
Implications for Education and Work
The implications of Nass’s research extend far beyond academic interest, touching on how we structure education, work environments, and even social interactions. For educational institutions, these findings raise critical questions about technology in classrooms and student study habits. If heavy media multitasking is associated with poorer cognitive control, educational strategies that encourage focused, single-task learning environments may be more effective than those embracing multiple simultaneous information streams.
In workplace settings, the findings challenge the common practice of encouraging employees to juggle multiple tasks simultaneously. As Nass noted in interviews, “Companies now create policies that force their employees to multitask. It’s not safe for people’s brains.” Organizations that structure work to minimize interruptions and allow for periods of deep, focused attention may see benefits in productivity and employee well-being.
The Social Dimension
Beyond cognitive effects, Nass’s later research explored how media multitasking might affect social and emotional development, particularly among younger users. In a 2012 study co-authored with Roy Pea and others, Nass found that heavy media multitasking in pre-teen girls was associated with negative social indicators, including reduced face-to-face social interaction and lower social well-being.
This social dimension of multitasking led Nass to advocate for the importance of face-to-face interaction. In one of his last public talks before his untimely death in 2013, he emphasized, “We’ve got to make face-to-face time sacred, and we have to bring back the saying we used to hear all the time, and now never hear, ‘Look at me when I talk to you.'”
Practical Implications: Reclaiming Focused Attention
If multitasking truly undermines our cognitive abilities, what practical steps can individuals take to mitigate these effects? Research suggests several approaches:
- Task batching: Rather than constantly switching between different types of tasks, grouping similar activities can reduce the cognitive costs of context switching.
- Technology management: Creating designated periods for checking email and social media, rather than allowing constant interruptions, can help preserve focused attention.
- Environmental design: Physical and digital environments can be structured to minimize distractions and support sustained attention.
- Mindfulness practices: Techniques that develop attention control may help counteract the tendency toward distracted processing.
- Digital sabbaticals: Regular breaks from technology may help reset attention patterns and reduce the habituation to constant stimulation.
Conclusion
Clifford Nass’s research fundamentally challenged our cultural celebration of multitasking, revealing the cognitive costs of dividing our attention across multiple information streams. While his statement that “multitaskers are terrible at every aspect of multitasking” may seem paradoxical, it reflects a profound insight: the very practice of multitasking appears to undermine the cognitive faculties needed to multitask effectively.
As our information environment continues to evolve, with even more sources competing for our attention, Nass’s work remains remarkably relevant. The true productivity enhancement may not come from dividing our attention but from reclaiming it—learning to focus deeply in an age of distraction. In this sense, Nass’s research doesn’t just identify a cognitive problem; it points toward a solution that may be increasingly valuable in our hyperconnected world.