This One Habit is Quietly Killing Your Focus

Your Slack pings are costing you more than you think.

You ever have one of those days where you feel busy, but somehow nothing important actually got done?

You bounced between 12 Slack threads, checked your email 48 times, joined three back-to-back Zooms, and opened (but didn’t finish) five browser tabs.

Welcome to the illusion of productivity.

You're Not Multitasking—You're Rapid Task Switching

Contrary to what you may believe, the brain cannot actually multitask.

What you’re doing is called task switching, and it comes with a mental tax you pay every time you shift attention.

A landmark study from the University of London found that multitasking during cognitive tasks caused IQ drops of 10 points—about the same as missing a night of sleep or smoking cannabis.

Let me repeat that:

Attention Residue: The Silent Killer of Deep Work

Even after you switch tasks, your brain keeps a “residue” from the last one.

Part of your cognitive power is still stuck in the Slack thread you just left, even while you're trying to write that investor update.

This means shallow thinking becomes the default. Strategic thought? Creative breakthroughs? Deep work?

Killed in the tabs.

The Hidden Financial Cost

Every time you tab-switch, you're fragmenting your focus and training your brain to expect novelty over depth.

• You make worse decisions.

• You miss compounding opportunities.

• You waste time on work that feels urgent, not important.

You’re handicapping yourself for no reason.

What High-Performance Founders Do Instead

The highest-leverage founders I know build in focus.

Not with hacks, but with systems:

• No-notification zones (yes, even for Slack).

• Calendar blocks for deep work—no meetings, no messages.

• One screen. One tab. One priority.

They treat their attention like capital. Because it is.

Here’s a nice overview:

TL;DR:

You’re not multitasking. You’re paying a cognitive tax every time you switch tasks.

It’s silently tanking your IQ, your strategy, and your bottom line.

Want leverage? Close the extra tabs.

Best,
Peter Delle