According to the Harvard Business Review when men and women are unethical, it's for different reasons. Men are unethical for themselves, while women are for others. Meaning guys may lie in order to gain a personal advantage, while women are more likely to be dishonest because they don't want to let others down.
You should definitely read the article linked in the tweet below because I learned a lot of other things about people being dishonest. Like how research suggests people tend to be more dishonest later in the day due to fatigue. When they're anxious people tent do look out more for themselves. But to learn more about why someone would act unethical on behalf of others click below!