Here’s my Q&A column from the WSJ this week — and if you have any questions for me, you can tweet them to @danariely with the hashtag #askariely, post a comment on my Ask Ariely Facebook page, or email them to AskAriely@wsj.com.

______________________________________________________

Dear Dan,

I recently saw an episode of “How I Met Your Mother” in which one of the characters says, “Nothing good ever happens after 2 a.m.” I totally agree. But why? Does the dark make us misbehave, or is it something else? How can we stay safe and responsible in the wee hours?

—Aaron 

You’re probably right that bad things are more likely to happen after 2 a.m. During the day, we face many temptations, and we overpower them with self-control.

But that control is like a muscle, and it gets tired from repeated use—not physical exhaustion but a mental fatigue that comes from making responsible, restrained choices over and over.

So when night falls, we can simply be too tired to keep being good and restrained—leaving us ready to fail.

______________________________________________________

Dear Dan,

I’m a high-school science teacher and a dean. We’ve had to discipline a number of students for cheating or plagiarism. Under our “two strikes and you’re out” policy, this puts them on the verge of getting kicked out of school after one infraction. The students were remorseful and confident that they would never again find themselves ripping off documents or copying papers—but then many of them cheated again. How can we better equip them to avoid such pitfalls?

—Morgan

It turns out that the fear of being caught doesn’t do much to deter crime in general. Even states that have the death penalty don’t report any noticeable difference in crime rates compared with those that don’t, according to a 2012 report by the National Research Council of the National Academies.

California’s “three strikes and you’re out” law was designed to take repeat criminals off the streets and deter offenders from repeated crimes. The theory was that if you knew that a third strike carried an especially harsh penalty, you would be deterred from further crimes.

But “three strikes and you’re out” didn’t seem to have a big effect on crime rates, according to a March 2000 study by James Austin and colleagues. And if “three strikes” didn’t work for crime, it’s unlikely to work for academic misdeeds.

We need to look for more effective approaches. Ultimately, what often stops us isn’t the fear of punishment but our own sense of right and wrong.

So you need to develop your students’ moral compasses. Maybe you should spend as much time on ethics as you do on math and history. After all, when they leave school, they’ll start applying their morals (whatever they are) to the world we share.

______________________________________________________

Dear Dan,

On a recent business trip to San Francisco, I showed up early for a meeting, so I went to wait in a coffee shop. A cup of coffee was $8, and it was full of young people. Don’t they have anything better to do with their money? Don’t they have jobs? Don’t they find it morally reprehensible to spend more than the hourly minimum wage on a cup of coffee?

—Maria 

I feel the same way. Still, it is all relative: If the liquid in question was wine, at just $8 a glass, we might not feel so offended. Maybe we need to be a bit less prejudiced against coffee.

See the original article in the Wall Street Journal here.