Texting is a distracting activity that affects concentration. Although many claim that it can be done while involved in another activity (so called multitasking), it is proven that it takes away one's focus and attention.
Aaron may think he can do both, study and text during a class because it seems easy to him. His mind will however wander to to person he is texting with, or to the content of the text. He might lose some piece of important information given during the class as he would be watching his phone during that time.
