Skill or Luck?

http://bit.ly/h1jpcZ . van den Steen says this in the abstract: "This
paper shows why... rational agents tend to
attribute their own success more to skill, and their failure more to
bad luck than an outsider." So, rational agents have biases? Isn't
this like saying rational people are irrational?

He also states that if 2 people do a job and you ask each what their
contribution was in percent., the sum is greater than 100%.

My father, who has high blood triglycerides, and my mother visited a
dietician to figure out a diet to decrease triglycerides. The
dieticians asked my dad what percent. of the meals he made. He said
50%. My dad never made a meal in his life. When they left the
dietician's office, my mother asked for an explanation. He said he
made all his breakfasts (cereal and milk) and half of his lunches (a
sandwich).

So this is what I think of when when someone says the sum will be
greater than 100%, and no one in my family would claim my father is
rational.

Brad