No, that question isn’t the beginning of a bad joke. But it could be the beginning of a psychology study.

In fact, a team of researchers in China recently did take it as the starting point for a study. In attempting to answer the question, they honed in on one factor that has previously been linked to both problematic internet usage and smoking: impulsivity.

Impulsivity is the tendency to act, well, on impulse. People with higher levels of impulsivity tend not to act according to a predetermined plan. They less often act according to inhibitions or self-control.

But the thing about impulsivity is that there are different type of impulsivity. In their study, the researchers found that problematic internet users and cigarette smokers tend to have in common high levels of attentional impulsiveness.

People with high levels of attentional impulsivity are less likely to pay attention to the task at hand and more likely to be distracted by extraneous thoughts. They often become restless in settings that require sustaining attention for an extended period of time. And, according to this study, they’re more likely to use the internet excessively and to take up smoking.

There were other types of impulsivity that were related either to internet usage or cigarette smoking, but not to both. For example, people with problematic internet use tended to score higher on motor impulsiveness, a tendency to act without planning or thinking. Smokers, on the other hand, tended to score high on sensation seeking, a tendency to seek out more stimulating activities and situations.

The finding that more impulsive people are more likely to smoke or use the internet in a way that interferes in their lives isn’t new. But this study sheds more light on what kinds of impulsivity are related to both smoking and problematic internet use, with attentional impulsiveness being a common thread between the two.