Mental State
We often hear how important mental health is, but less about how brain illnesses don’t just impact our mood—they can cloud our sharp thinking too. Anxiety and depression can lower your cognitive ability not just temporarily but for the long haul, by as much as 10 IQ points. Chronic stress—which is hard to escape these days—also takes a toll, reducing intelligence by about 5 points.
Being Idle
A little downtime feels good for everyone, but laziness should be kept in check. Both body and mind need activation because what we don’t use starts to fade—and the brain is no exception. A consistently lazy lifestyle can cost you up to 5 IQ points.
Sounds
Harmful noises disrupt focus and rest. Few realize that noise pollution is seriously damaging, so living near a busy highway or airport isn’t great for your brain either—it can lower your IQ by up to 4 points.
Deficiency
Vitamin deficiencies affect not just the body but also mental health. Especially lacking vitamin D, B12, iron, and iodine can drag your IQ down by as much as 12 points. The best way is to get these nutrients from sunlight and a healthy diet, but in winter or if your diet falls short, supplementing with vitamins is essential.
Sleep
We know lack of sleep has serious health effects, but it also dulls your mind. Sleeping less than six hours a night for a long time can reduce your IQ by 7 points.
Distracted
Multitasking is trendy—or more like necessary with how busy life is—but constantly juggling tasks can cost you 5 IQ points. Avoid spreading yourself too thin; rushing and constant distraction take a real toll.
Substances
Addictions destroy our body, soul, and mind. Alcoholism and drug use can lower your IQ by as much as 7 points.
Staring
Older generations often worry about young people staring at screens all day—and they’re right. The constant flood of information and stimulation dulls intellectual ability. Spending more than six hours daily in front of screens—whether monitor, TV, tablet, or phone—can reduce your IQ by 4 points, especially affecting attention and processing skills.
Stimulation
The opposite of the previous point: a lack of stimulation—especially in kids and young people—can harm the brain just as much. That’s why neglected children raised in low-stimulation environments tend to be less sharp than peers who had more play and parental engagement.
Pollution
Environmental pollution threatens more than just our bodies. Surprisingly, living in highly polluted areas can lower your IQ by 2 to 3 points. This includes living near chemically contaminated rivers, smoggy city air, or factories emitting harmful substances that pollute soil.
