Left-handed people have their own advantages. Left-handed people have the ability to give full play to the left and right areas of the brain, which makes them superior in many fields. Left-handed people are good at intuitive thinking and have artistic talent; Left-handed people can use the "nerve short circuit" in the right brain to attack each other quickly and win by surprise in antagonistic sports with high requirements for nerve response; Especially in the field of mathematics, left-handed people are more noticeable. According to the research of scholars from Hopkins University in the United States, among children with mathematical talent, left-handed people are almost twice as many as ordinary people. The disadvantage of left-handed people is that they will encounter some inconvenience in their daily life, because most people use their right hands, so most daily necessities and facilities are designed for right-handed people. Modern medical research has proved that the right hemisphere of left-handed people is dominant, and the role of the right hemisphere of the brain focuses on emotion, intuition and artistic thinking, so they are more prone to emotional frustration and various psychological problems. Left-handed people are more likely to suffer from autoimmune diseases, such as diabetes, rheumatoid arthritis, myasthenia gravis and so on.

Left-handers are also called "left-handers", which means people who are more accustomed to doing things with their left hands. "Profit" refers to your own hands.