There are competitions that honest people regularly do poorly at, because liars have an advantage. Mating and attracting venture capital are examples. I knew a kid who claimed to have had sex with 100 women by the time he was 20. "How?" I asked. "I told them all I loved them," he said.

(Though, in my experience, telling women you love them before you've had sex with them is more likely to get you labeled 'creepy' than get you laid. Maybe it's different for teenagers.)