Researchers at Kent State University conducted a study of five hundred students and found that frequent smartphone use was associated with lower grades, higher anxiety, and reduced happiness. People who spend a lot of time on their devices are more vulnerable to social comparisons, and that leaves them feeling a sense of emptiness. The fear of “missing out” and feeling inadequate makes it difficult for people to stay present and happy in their own lives. So, a caution: use your smartphone in moderation.