Pfft. A five year old can be deceptive. A dog can be deceptive. Deception is easy, and often the easy way out. Being honest is hard - but it's worth it.

You only get one life. If you spend it lying to everyone, you'll end up not even learning who you are.

People with the built-in social surveillance software called "conscience" have a hard time to be deceptive without feeling bad about themselves. For most people it's way easier to be honest.

Not being deceptive is also an evolutionary advantage because people can trust you and you earn a position of respect in your group. Evolutionary psychology is popsci trash, you can invent just-so stories for any number of claims using it.