Reference Terms
from Wikipedia, the free encyclopedia
Left-handed
A person who is left-handed primarily uses his or her left hand, more so than the right hand; a left-hander will probably use the left hand for tasks such as personal care, cooking, and so on. Writing is not as precise an indicator of handedness as it might seem, because many left-handed people write with their right hand but use their left hand for other tasks. Approximately 8 to 15% of the adult population is left-handed. Studies indicate that left-handedness is more common in males than females. Left-handedness, in comparison to the general population, also appears to occur more frequently in identical twins, and several groups of neurologically disordered individuals (people suffering from epilepsy, Down's Syndrome, autism, mental retardation, dyslexia, etc.)There have been many famous left-handed people, and the associated right brain hemisphere that is said to be more active in left-handed people has been found in some circumstances to be associated with genius and is correlated with artistic and visual skill.
Related Stories
1
2
Mind & Brain News
May 20, 2026
May 20, 2026 Women may be especially sensitive to the effects of common dementia risk factors, according to a new UC San Diego study of over 17,000 adults. Researchers say tailoring prevention strategies specifically for women could be key to reducing ...
May 20, 2026 A newly identified enzyme called IDOL could become a major new target in the fight against Alzheimer’s disease. Researchers found that removing it from neurons sharply reduced amyloid plaques and improved key brain processes linked to resilience ...
May 17, 2026 Scientists have discovered that the human body undergoes a dramatic internal transformation during extended fasting, with major changes appearing only after about three days without food. In a seven-day water-only fasting study, researchers tracked ...
May 16, 2026 Exercise may be training your brain just as much as your body. Researchers discovered that certain brain cells stay highly active even after a workout ends, and those lingering signals appear to help the body build endurance over time. In ...
May 16, 2026 Researchers have shown for the first time that malfunctioning mitochondria — the cell’s energy generators — may directly cause cognitive decline in neurodegenerative diseases. By creating a new tool that temporarily boosts mitochondrial ...
May 16, 2026 A major analysis of brain scans found that people with anxiety disorders have noticeably lower levels of choline, a nutrient crucial for healthy brain function. The strongest evidence appeared in the prefrontal cortex, the region tied to emotional ...
May 15, 2026 You may not need hours at the gym to boost your health after all. Researchers say just 30 minutes of high-intensity exercise per week — broken into tiny bursts of effort that leave you out of ...
May 15, 2026 Cannabis use among older adults is rising fast, but today’s marijuana is far more potent than many people realize — and experts warn the risks may be underestimated. Stanford Medicine specialists ...
May 15, 2026 Scientists have uncovered evidence that serotonin — the same brain chemical boosted by many antidepressants — may actually worsen tinnitus. Using advanced light-based brain stimulation in mice, researchers identified a serotonin-driven circuit ...
May 13, 2026 UC Davis researchers created brand-new psychedelic-like compounds by shining UV light on amino acid-based molecules. These compounds activated key serotonin receptors tied to brain plasticity and mental health benefits, but surprisingly did not ...
May 13, 2026 A huge long-term study found that drinking two to three cups of coffee a day was linked to a much lower risk of dementia, especially before age 75. Researchers say caffeine may help keep brain cells active while reducing inflammation and harmful ...
May 13, 2026 The little pauses, “ums,” and moments when you struggle to find the right word may reveal far more about your brain than anyone realized. Researchers discovered that everyday speech patterns are closely tied to executive function — the mental ...
Latest Headlines
updated 12:56 pm ET
May 18, 2026 A new study suggests humans became overwhelmingly right-handed because of two major evolutionary shifts: walking on two legs and developing much larger brains. Researchers found that as human ...
May 11, 2026 An ancient Chinese exercise routine may be just as powerful as a daily brisk walk for lowering blood pressure — without equipment, gyms, or intense workouts. In a major clinical trial, adults with ...
May 11, 2026 A new study suggests AI chatbots may do more than spread misinformation — they can actively strengthen a user’s false beliefs. Because conversational AI often validates and builds on what users ...
May 10, 2026 Scientists have uncovered a hidden “stop-scratching” signal in the nervous system that tells your brain when enough scratching is enough. The discovery centers on a molecule called TRPV4, which ...
May 7, 2026 Eating eggs might do more than just start your day—it could help protect your brain. Researchers found that people 65 and older who eat eggs regularly have a significantly lower risk of developing ...
May 6, 2026 A new twin study suggests your genes may play a bigger role in your future success than your upbringing. Researchers found that IQ, which is largely genetically influenced, strongly predicts ...
May 4, 2026 A new study suggests travel could be a surprisingly powerful anti-aging tool. By viewing tourism through the lens of entropy, researchers found that positive travel experiences may help the body stay ...
May 4, 2026 A new study suggests a surprisingly simple compound could help fight Alzheimer’s disease. Researchers found that arginine—an inexpensive amino acid already considered safe—can reduce the ...
May 4, 2026 Creatine might be famous in the gym, but its real story is far more interesting. Naturally produced in the body, it helps power cells by rapidly regenerating ATP—the fuel that keeps muscles, the ...
May 4, 2026 A new study suggests depression may soon be detectable through a simple blood test—by tracking how certain immune cells age. Researchers found that accelerated aging in monocytes, a type of white ...