Testosterone is to blame

The argument

The most common theory about why women tend to outlive men is that of biological differences, and on this account the difference that matters most is hormonal. The high levels of testosterone found in men tend to have serious long-term effects on overall health. The argument's structure is a trade-off across time: testosterone is responsible for physical strength in the short-term, but its long-term presence spells a whole host of issues for the male body, such as heart disease, infections, and cancer. What benefits a body over years is not the same as what serves it over decades, and a difference that accumulates slowly can express itself as a difference in lifespan even where it is barely visible at any given moment. A second biological difference is offered as reinforcement, working through the same cardiovascular pathway. Other issues, such as differences in fat storage, contribute to overall poorer health in men. Men tend to have more visceral fat, which surrounds the organs, in comparison to subcutaneous fat, which is under the skin and more commonly seen in women. That distinction is not cosmetic on this account but anatomical, since fat surrounding the organs can have long-term effects on health issues such as cardiovascular disease, exposing those organs to a burden that women's pattern of fat storage places elsewhere. The comparison is completed on the other side. The higher levels of estrogen found in women work as somewhat of an antioxidant for the female body, which helps to prevent the onset of cardiovascular disease for much longer. This means the hormonal difference is not simply that men carry a risk factor women lack, but that women carry a protective factor men lack, so the two effects push in opposite directions on the same disease. Taken together, proponents conclude, male hormones contribute to poor male health, and testosterone is to blame for much of the gap in life expectancy.

Premises

Counter-arguments

While it is a common theory, this is not a definitive explanation as to why men die younger than women. Higher levels of testosterone are completely normal in the male sex and do not necessarily mean that they are more likely to die than women. Statistics show that the number one cause of death in both men and women is heart disease, and the average age difference in death has not been proven to be due strictly to hormones.

Rejecting the premises

[Rejecting P1] The counter-argument on record makes the basic objection: testosterone at male levels is normal physiology, and showing that a hormone is present in the group with the shorter lifespan does not establish it as the cause. The mechanism is asserted rather than traced. [Rejecting P2] Visceral fat distribution and cardiovascular risk are real associations, but they are heavily modified by diet, activity, alcohol and smoking, all of which have differed sharply by sex across the same populations and periods. The premise treats a pattern shaped by behaviour as though it were purely endocrine. [Rejecting P3] The oestrogen claim is the weakest link. It predicts that supplying oestrogen would extend life and protect the heart, and the large randomised trials of postmenopausal hormone therapy did not find the cardiovascular benefit the observational picture had suggested — some arms found harm. An account that fails its own most direct test cannot carry the conclusion. [Rejecting C] The size of the gap also varies substantially between countries and has narrowed and widened within single populations over decades, which a fixed biological difference cannot explain but differences in smoking rates, occupational hazard, violence and help-seeking can.