"In the study by Sana, Weston and Cepada, students who engaged in multitasking expected that it would hinder their learning a fair bit (a mean of 5.5 on a 7-point scale), but thought it would barely hinder that of their peers (a mean of 3.3). And in the study with multitasking confederates, participants estimated that seeing others multitask had barely hindered their own learning (a mean of 2.7).
Yet having multitaskers in view did have a considerable impact on learning. In fact, the negative consequences of observing multitasking were even greater than those of performing multitasking oneself (perhaps because the multitaskers could time their multitasking to suit their own needs), counter to students' expectations. Neither multitaskers nor their neighboring victims realized the cost of merely observing multitasking." Read More