A SEP IRA (Simplified Employee Pension) is a retirement plan that is popular with many small business owners and self employed individuals. The 2015 SEP IRA contribution limit is $53,000 (the 2014 SEP limit is $52,000).
Meanwhile, other studies suggest that another gene, DRD4, may also play a role in traits such as shyness and anxiety. The DRD4 gene codes for a protein that binds dopamine, another chemical messenger that has powerful effects in the brain. Again, the DRD4 gene comes in two forms: a long and a short version.
In a 2014 U.S. study surveying procrastination and impulsiveness in fraternal-and identical twin pairs, both traits were found to be moderately heritable. The two traits were not separable at the genetic level (r genetic = 1.0), meaning no unique genetic influences of either trait alone was found.