Genetics also contribute to left-handedness. Parents who are both left-handed have a 50 percent chance of having left-handed children. Parents who are both left-handed have just a 2 percent chance of lefy offspring. Women no become pregnant when they're older than 40 are more likely to have left-handed children. And for unknown reasons, left-handedness is more common in antical twins than other births. Left-handedness is more common in men than women. Scientists suggest having more estosterone slows the left side the brain from developing, taking the right side of the brain minorant. Brain association is positive, so left-handed people's minute side of the brain is the ht. Just as the cause is unknown are theories of whether left-handed people are more prone to diseases and an early death. A 2000 study by Canadian researchers and that being left-handed is more common in people who are bian or gay. Research published in the British Medical Journal concluded at left-handed women are more likely to be diagnosed with breast cancer. The study found that nuthpaws are more than twice as likely to have breast cancer before enopause. Another theory states that ties die earlier because of the stresses of living in a right-ended world. A 1991 edition of the Psychology Bulletin citedSpan studies that found that a number of lefties decreasesolder age groups. The research included lefties don't live as long.1994 study published in the British Medical Journal found that ties are more likely to die fromnatural causes. The research and a strong association with National Left-Handed Day Whether you're a southpaw or just want to celebrate them, the annual celebration is Aug. 13. Ellen Young, Lawrence resident, likes that she's a little different from everybody else. She takes this day every year to display her southpaw pride. Young wears a button and receives calls from friends and family acknowledging her special day. Young has been celebrating since 1996. Her lefty pride continues year-round. Young visited a left-handed store in Branson, Mo., and bought a T-shirt that says "I may be left-handed, but National Left-Handers Day deaths during wars. Other studies, including those by English neurologist Simon Ellis, found handedness unrelated to lifespan. Despite the research suggesting that lefties have more health problems, being a southpaw has its benefits, which some attribute to brain lateralization. The health effects of lefthandedness don't always wait until adulthood to emerge. Children who are left-handed are up to three times more likely to be diagnosed with juvenile diabetes than right-handed children. Life as a lefty Fifty years ago, teachers punished students who were United States Presidents also have a higher rate of left-handedness than the average population, roughly one in three, according to The Lefty Notebook. All the 1992 presidential candidates were left-handed — George H.W. Bush, Bill Clinton and Ross Perot. The left and the right hemispheres of the brain are specialized for certain functions. In general, the left side of the brain specializes in logical, analytical, objective thinking. The right side of the brain focuses on subjective, random, intuitive thinking.