1. They’re more addictive than crack. The CrackBerry isn’t just a clever nickname. In a recent study, people reported that they found it harder to resist checking social networks than to say no to alcohol or cigarettes. But that’s not because e-mails produce so many feel-good brain chemicals; it’s because e-mail is cheap and easy to check. The same study found that participants had a stronger urge to do work than to e-mail or surf the Web.
2. They’re dulling our memory. With smartphones, we can look up anything at any time, leading to concerns that our reliance on the magic answer box will make it harder to recall details on our own. Even though researchers found that people remembered where facts were stored on a computer better than the actual data, that isn’t evidence of less memory — just of a different kind.
3. Short texts are a product of shortened attention spans. The father of cell-phone texting, Friedhelm Hillebrand, didn’t limit texts to 160 characters because of our brains. He did it because of the telecom industry’s bandwidth limits. He studied earlier communications and found that most postcards and telex messages used fewer than 160 characters.
MORE: Read about the TIME Mobility Poll
MORE: Read TIME’s Special Report On How Your Phone Is Changing The World (and your life) Here