A bigger opportunity arose with my 8-year-old son. Though he didn’t know anything about the journal, after a few weeks, he seemed to open up in a new way, asking me things he was too embarrassed or scared to ask before, like what the word “pimp” meant and why people kill themselves. In fact, one of my biggest takeaways was that we shouldn’t lie to children when they are asking us about grown-up words or ideas — otherwise, they will just ask Siri. If it’s between YouTube and me to explain prostitution, I pick me.

Still, I wondered about those little lies we tell to avoid hurting people’s feelings. Researchers at the University of California San Diego Emotion Lab are looking at “prosocial” lies — the white lies we tell to benefit others, like telling an aspiring writer a story is great because you want to be nice and encouraging, when in reality you know it needs work and will meet rejection. A recent study at the lab suggests that we are more likely to tell a prosocial lie when we feel compassion toward someone, because if you feel bad for someone, the last thing you want to do is hurt him or her with the truth. These lies feel better in the short term, but they often do more harm than good in the long term. After all, the brutal truth can be painful, but people need to know it if they are to improve their performance, especially in a work or school situation.

But was brutal truth what I really wanted when it came to my marriage?

My focus on honesty at times did lead to better interactions with my husband. When the New York Times Magazine article about open marriage came out, for example, it sparked my curiosity. Since I was keeping an honesty journal, rather than keeping it to myself, as I would have done in the past, my husband and I had an honest discussion about it. Other times, the compulsion to be honest strained things between us. That I disagree with some of his parenting techniques doesn’t necessarily need to be pointed out every single time. I came to realize that, within relationships, there is a third category between dishonesty and telling white lies, called not sharing everything.

Over all, I found that I struggled more with the small instances of honesty, rather than the big. So, when a client accidentally paid me twice for a project — sending a duplicate $1,000 check a week after they’d already paid me — there was no internal debate. It was $1,000, so obviously, I notified the client. But when the McDonald’s drive-through cashier gave me an extra dollar in change and the line had been SO long and all I wanted was a Diet Coke and my kids were acting crazy in the back seat and why was this stupid McDonald’s always so slow anyway?!… it was a different story. Even though I gave the dollar back, I almost didn’t, because an extra dollar was such a small thing and seemed somehow justified. Had I not been focused on honesty, I’m not sure I would have given it back.

My experience was consistent with what the behavioral economist Dan Ariely wrote about in his 2012 book, “The (Honest) Truth About Dishonesty.” His research showed that we fudge the truth by about 10 percent or so. We cheat when we are fairly certain we can get away with it, but just by a little, and about things we can justify. We do it more if we see other people doing it. We do it less if we are reminded to be honest. My journal pointed these instances out to me rather starkly.