Some scientific studies have shown that people who are right handed generally live longer than people who are left handed. The amount varies from study to study-some say righties will live a few months more and some say righties live up to nine years more. Although the amount of time longer a righty lives is not clear, the truthfulness of the claim seems pretty clear.
To put the claim in terms of two aspects of critical thinking-Correlation vs. Causation and Occam’s razor: The world is geared toward people who are right handed since the majority of the population (85-92%) is right handed. Since the world is geared toward righties, that would make tasks a little more difficult on lefties. Most machines are usually built with a bias towards righties and even if someone who is lefty has the same motor skill level as his counterpart, it would still be a little harder for him to use the machine. An experiment in the 1980’s found that 15% of 20 year old people were left handed, but only 1% of 80 year old people were left handed. The conclusion of that study was that righties live longer than lefties and later experiments continued to find that there was a difference in the life expectancy between right and left handed people (Replicability). One way that lefties are at a disadvantage is with automobiles, it was found that left handed drivers were twice as likely to have a crash and 4x as likely to die from injuries sustained in the crash than right handed drivers.
One important thing to consider from this is should the world be more lefty friendly? Although it would be unrealistic and even unnecessary to change everything, it is important to change aspects of the world that have a lot of impact on people-such as the automobile industry. Perhaps if we geared automobiles to be more lefty friendly, there would be fewer accidents and that would be a benefit to all. Nothing against lefties, but this is one of those times I like to be in the majority.
The graying of America: an encyclopedia of aging, health, mind, and behavior By Donald H. Kausler, Barry C. Kausler
http://books.google.com/books?id=CV6-ctzUXysC&pg=PA199&lpg=PA199&dq=right+handers+live+longer+than+left+handers&source=web&ots=Qpzm_H7_fo&sig=xvT9mLg3eizmMMQj6DWrVMSJcDU#v=onepage&q&f=false
