 The smartphone has become an integral part of our daily lives, offering us constant access to entertainment, information, and social connections. However, its ubiquity can have a detrimental effect on our ability to concentrate and focus on tasks at hand. This study investigated whether the mere presence of a smartphone affects cognitive performance by measuring participants' reaction times when performing a concentration and attention test with or without their phones present. The results showed that participants were slower and less accurate when their phones were present, suggesting that the phone was consuming their mental resources and reducing their ability to focus. These findings support the hypothesis that the mere presence of a smartphone reduces cognitive performance. This article was authored by Jeanette Scouronyk, Andrea Seifert, and Sven Lindbergh.