The Surprising Reason Why Multitasking Lowers Your IQ by 10 Points

In a world that rewards speed and efficiency, multitasking has become the ideal benchmark for productivity. We balance emails while participating in virtual meetings, reply to messages while tackling complicated reports, and scroll through social media while watching television. It seems like we are accomplishing more in a shorter amount of time. However, what if multitasking is causing more harm than benefits? Studies indicate that the human brain is not designed for multitasking, and trying to do so can temporarily reduce IQ by as much as 10 points—similar to the effects of not getting enough sleep.

The Myth of Multitasking

Contrary to popular belief, multitasking does not mean doing multiple tasks simultaneously. Instead, it involves rapidly switching between tasks. Neuroscientists have found that the brain cannot focus on two cognitively demanding activities at the same time. What we perceive as multitasking is actually “task-switching,” and it comes at a cognitive cost.

Individuals who engage in heavy multitasking experience a decline in cognitive performance equivalent to losing an entire night’s sleep. A study from Stanford University revealed that frequent multitaskers struggle with filtering irrelevant information, switching between tasks efficiently, and maintaining sustained attention. This means that rather than increasing efficiency, multitasking makes us slower, less accurate, and more mentally exhausted.

The IQ Drop: What’s Happening in Your Brain?

When you switch between tasks, your brain undergoes what’s known as a “cognitive cost.” The prefrontal cortex, the region responsible for focus and problem-solving, must constantly disengage from one task and reorient itself to another. This process, known as “attention residue,” results in a loss of mental energy and effectiveness.

The 10-point IQ drop observed in multitaskers is due to increased cognitive load and reduced working memory capacity. Multitasking can even cause long-term structural changes in the brain. MRI scans showed that individuals who frequently engage in media multitasking had less gray matter density in the anterior cingulate cortex, the part of the brain responsible for decision-making and emotional control.

To put this into perspective, an IQ drop of 10 points is similar to the impairment experienced by someone who has stayed awake for 24 hours. It is also equivalent to the cognitive decline seen in individuals under the influence of marijuana. This means that multitasking can temporarily make us significantly less intelligent and capable.

The Hidden Costs of Multitasking

Aside from lowering IQ, multitasking comes with several hidden costs that can negatively impact performance and well-being:

• Reduced Productivity – A study by the American Psychological Association found that task-switching can reduce productivity by up to 40%. Each time you switch tasks, your brain needs time to reorient itself, leading to wasted mental effort.
• Increased Errors – Research from the University of California, Irvine, indicates that individuals who frequently switch tasks make more mistakes than those who focus on one task at a time. This is particularly concerning in fields that require precision, such as medicine, law, and finance.
• Higher Stress Levels – Multitasking increases the production of cortisol, the stress hormone. The constant shifting of attention creates a sense of mental overload, leading to feelings of anxiety and burnout.
• Weakened Memory – Chronic multitaskers struggle with working memory and information retention. They have difficulty filtering out irrelevant information, leading to poor recall and comprehension.
• Lower Emotional Intelligence – Constant multitasking reduces self-awareness and emotional regulation. When your brain is overwhelmed with multiple inputs, it becomes harder to engage in deep conversations, read social cues, or respond empathetically.

How to Break the Multitasking Habit

Given the overwhelming evidence against multitasking, it’s crucial to adopt strategies that promote deep focus and efficiency:

• Use the Pomodoro Technique – Work in 25–50 minute focused intervals followed by short breaks. This minimizes task-switching and enhances concentration.
• Prioritize Tasks – Organize tasks by importance and tackle them sequentially rather than simultaneously.
• Eliminate Distractions – Turn off notifications, set boundaries with colleagues, and create a dedicated workspace to improve focus.
• Practice Mindfulness – Engaging in mindfulness meditation has been shown to improve attention span and cognitive function.
• Single-Task with Purpose – Train your brain to focus on one activity at a time. Whether reading, writing, or problem-solving, give your full attention to the task at hand.

Also read: 5 Personal Development Books That Will Surprise and Inspire You

Final Thoughts

Multitasking might appear to be an essential ability in our fast-moving world, but research indicates otherwise. Rather than enhancing productivity, it drains cognitive resources, reduces IQ, and increases stress levels. A single-tasking approach can retrieve your concentration, improve your mental performance, and ultimately work more intelligently—not just harder.

Would you choose temporary efficiency at the cost of long-term cognitive decline? The choice is obvious—abandon multitasking and harness the power of focused attention.