====== Lifespan variations ======

In general, the lifespan for human males is around 5% shorter than for females. Though this phenomenon has been self-evident for millennia, the reasons for the difference are still unclear.

There are many theories, which include biochemical, social, psychological and behavioural factors (no particular order)

  * There could be hormonal differences which somehow affect lifespan
  * Larger individuals (i.e. males) tend to have shorter lives
  * It's possible that men are less risk-averse
  * Males tend to be more prone to substance abuse
  * Men are more prone to suicide 
  * Unidentified genetic reasons e.g. chromosome X effects
  * Armed conflicts
  * Females tend to be more aware of self-care
  * &etc.

It's currently thought likely that there are a combination of causes, but there is no general agreement on which factors might be the most important.

As an added complication, in humans, it's now known that, in general, women tend to experience more health problems during their lifetime - whilst also living longer. This is now known as the //'Health Survival Paradox' //(see [[https://en.wikipedia.org/wiki/Health_survival_paradox|Wikipedia]])

Further reading and general info., see: [[https://en.wikipedia.org/wiki/Life_expectancy|Wikipedia]]

Note that many other animals show a similar pattern, notably some of the great apes, and some species of fish. Across //all //species, however, there are large numbers of exceptions.