This work presents a new mathematical expression for middle and old age mortality as an alternative to the classic Gompertz-Makeham model. Whereas old age mortality is driven by biological aging, middle mortality is mainly caused by behavior. To test the model, sex differences in life expectancy and mortality in Europe from the mid-nineteenth century until recent periods are investigated. The here presented mortality model shows that the female advantage in life expectancy and its dynamics are mainly caused by male risky life style.