We know that males and females have minor and major differences in many aspects — attitude included. Generally, males of most species are more aggressive, while the females are less aggressive. Researchers from China, Taiwan, U.S, and U.K have found evidence that might suggest that aggressive tendencies may lead to a shorter lifespan.
Scientists have been theorizing about the reason for females of most species living longer than males for many years. Some have suggested it has something to do with the differences in hormones, others that it has to do with deleterious mutations in mtDNA passed down from mothers. But the strongest argument has been that it comes down to aggression in males—mostly due to competing for a mate. In many species, fighting for a mate results in both injuries and high stress levels.
(Image Credit: Wen-Sang Huang)