This might sound unbelievable, but scientific studies have shown that people are more likely to tell lies in the afternoon.
Thanks to the 'morning morality effect', you are more honest when you wake up, but your morals slip as the day goes on. Statistics show that people are 20-50% more likely to be dishonest in the afternoon. And it's because you get tired. The less energy you have, the harder it is to stay ethical.
Another study found that night owls are more likely to stay ethical after lunch than early risers, because they feel more rested in the afternoon.
So what's the moral of the story? Make those tough ethical decisions when you're refreshed after a good night's sleep. Honestly. We're not making this up.