Why Are 1 in 10 People Left-Handed? Do they live less.

Only 1 in 10 humans is left-handed—and fossil records show this exact ratio has remained unchanged for over 400,000 years. In a world designed almost entirely for right-handers, why didn’t evolution eliminate left-handedness? And did that infamous 1991 study claiming left-handers die 9 years younger actually get debunked? In this video, we explore the science and history behind human handedness: from ultrasound movements in the womb and genetic clues in the spinal cord, to the combat advantage that kept left-handers alive throughout human history. TIMESTAMPS: 0:00 The 1991 Headline & The 10% Mystery 1:13 A World Built for Right Hands 1:42 The History of Forcing Left-Handers to Switch 2:17 Where Handedness Begins: In the Womb 3:28 The Genetics Behind Left-Handedness 4:58 The Fighting Hypothesis: An Evolutionary Edge 6:23 Why Humans Are So Lopsided (Cooperation vs. Competition) 7:11 The Truth Behind the "9 Years Younger" Study 8:08 Why Nature Kept Left-Handers #science #evolution #biology #psychology #explainforge