Popular theory has long suggested that women have a greater life expectancy than men due to behavioural differences - men have more dangerous jobs, drink and smoke more, and are slow to seek advice from doctors. However, researchers at the University of New South Wales have found that having two copies of the same sex chromosome is associated with having a longer lifespan, with the second copy offering a protective effect. PhD Candidate and co-author of the research Zoe Xirocostas explains the 'Unguarded X' hypothesis.
Zoe Xirocostas Photo: Supplied
