Final answer:
Life expectancy at birth is typically higher for females than for males. As adults age, their life expectancy increases due to overcoming earlier life mortality risks, with women generally outliving men. Global life expectancy averages at 73.4 years, and is influenced by several factors including healthcare and lifestyle.
Step-by-step explanation:
The subject in question pertains to life expectancy differences and trends with regard to gender and age. In 2010, life expectancy at birth in Australia was 79 years for males and 84 years for females. Interestingly, as adults age, their life expectancy can actually increase, because those who have reached a certain age have already surpassed the mortality risks of earlier life stages. If a man is 65, his life expectancy may increase compared to the average at birth, and it increases further if he reaches 80. The same trend is seen in women; a 65-year-old woman will have a higher life expectancy than the average at birth. For example, in the United States in 2015, life expectancy at birth was 77 years for males and 82 years for females, but life expectancy for individuals who have reached 65 would be higher.
It is important to note that life expectancies vary globally, with an average of 73.4 years across countries. Certain factors such as nutrition, healthcare, environment, and lifestyle choices play a significant role in determining average life expectancies. In terms of gender differences, women generally tend to outlive men, and this phenomenon has been consistently observed across various nations.