Today’s smartphones enable business leaders to constantly be in contact with the office and access the Internet or the cloud for needed information on the fly. Unfortunately, it is exactly this constant contact and easy access that often overwhelm the positives and make these devices harmful to the leaders’ businesses and lives.

Constant contact leads to a triumph of the urgent over the important. With the emails rolling in and the Internet so accessible, too much time is spent responding to trivial matters or checking the news, stocks or sports scores. These constant interruptions and distractions all but eliminate the quiet time leaders need to think about their businesses.

Constant contact leads to micromanagement. Leaders can know what is happening in their businesses at all times. This lets leaders contribute their two cents on every issue. The resulting barrage of emails, text messages or phone calls to their teams interrupts the day and undermines their authority and autonomy.

Constant contact leads to wimpy teams: Teams know that their leaders can always be reached for an opinion or seal of approval. So even insignificant decisions are run by leaders, with the leaders serving as a security blanket for team members unwilling to make a decision for which they would then be held accountable.

Smartphone usage is often inefficient. Tapping out a response on smartphones, even for texting wizards, is nowhere near as efficient as touch typing on laptops. As such, all but the simplest emails are often read and handled twice, once on the smartphone and once on the laptop.

Leaders should ask themselves, “Am I going to work high?” Constant multitasking that results from excessive smartphone usage reduces their ability to function at peak levels. A study conducted by TNS Research determined that workers distracted by phone calls, emails and text messages suffer greater losses of IQ than people smoking marijuana. These effects accumulate. Without downtime to recharge batteries, people’s stress levels increase with damaging effects on cognition and physical health.

Smartphones also make leaders both absent and rude. Leaders should try having a meeting, casual conversation or meal where everyone is present and listening intently to whomever is speaking.

It just ain’t happening anymore!

Lastly, leaders are setting a lousy example. Their teams are aping their behavior. Many can no longer work for solid blocks of time and actually require interruptions and distractions to keep things interesting and lively.

Of course, smartphones don’t kill businesses, but poor leadership does. Smartphones enable leaders to do more, leading to poor management skills, inefficient work style and weak time management skills that are even more detrimental.

To be used effectively, smartphones require discipline and self-control. Here are some additional tips for business leaders:

• Create time-outs from smartphones, especially during the most productive time of the day, at nights and on weekends.

• Set up rigorous controls on how often emails are received (do not use automatic syncing).

• Set up time locks that prevent access to games, nonwork apps and even the Internet.

(Editor’s note: This piece originally appeared on the Wharton Blog Network.)