Why men forget and women's birthday?

From a Norwegian study shows that in fact, women have no good reason to feel neglected, if the spouse or partner has forgotten that she has birthday.

Men are generally forgetful, and this is associated with sex, so it is born and unconditional.

Researchers at the University of Science and Technology in Norway, after analyzing the responses received from 40 thousand volunteers of both sexes, who were asked in advance for their partners birthdays, names, events and several other questions, nine such, concluded that 89.7% of men had difficulty with names, compared with 86.5% of women.

Likewise, 79.4 of men had difficulties in memory of important dates, versus 64.7 for women.
What emerged from the experiment also showed that males were more forgetful those aged from 30 to 60 years.