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.

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Dear Dan,

A friend told me recently that wearing a bike helmet is actually more dangerous than not wearing one because those who wear a helmet take more risks, which outweighs the benefits of having their heads protected. Should I tell my kids to stop wearing helmets?

—Phil 

Definitely not, but the question is a complex and interesting one. The real issues here are: what kinds of injuries helmets can prevent, how wearing a helmet alters our behavior and how our risk-taking changes over time.

Let’s think for a minute about a related case: seatbelts. When drivers, pushed by legislation, began to wear seatbelts as a matter of course, they might have felt extra-safe at first, making them think that they could get away with driving more aggressively. But after a while, as wearing a seatbelt became fairly automatic, that sensation of cocooning safety subsided. The tendency to take extra risks subsided too. So the full benefits of seatbelt use only emerged after we got used to wearing them all the time.

The same can be said about helmets. When we initially put one on, we may feel overconfident and cut more corners with road safety. But once helmet-wearing becomes a habit, we should revert to more prudent behavior, which will let us realize the helmet’s full benefits. That’s especially important, of course, with children.

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Dear Dan,

I’m finding dating tricky these days. I’d like to show some chivalry, but it isn’t clear how to do that. Try as I might to pay the bill for dinner as a sign of respect and care, the women I’ve been out with seem to want to split it. Any advice?

—Ron 

Acts of chivalry are acts of respect. They aren’t about practicality but about doing something kind for the other person. So I would suggest instead that you open the car door for your dates.

Decades ago, when car doors had to be unlocked manually, it was customary for the driver to open the door for the passenger. These days, when car locks release with a click and a beep from a keychain, doing so seems like a pointless gesture.

But that only makes it a stronger signal of chivalry: You don’t have to open your date’s door to let her in or out, but by choosing to do so, you offer a true act of consideration and caring. And it’s not only a nice gesture–it’s cheaper than picking up the tab.

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Dear Dan,

Why don’t people bike more? Bicycles are amazing vehicles—fast, efficient, easy to park, good for our health and our planet. What’s holding us back? 

—Ziv 

Simple: hills. Bicycles are fine things, and technology will no doubt continue to make them lighter, faster and safer. But all of these improvements aren’t likely to overcome our laziness—our deep-seated desire to move through the world with as little effort as possible.

See the original article in the Wall Street Journal.