But one of the key findings of the study is that this multitasking didn’t do a very good job of satisfying their cognitive needs which actually motivate the multitasking in the first place, Wang said. That’s probably because their other media use distracted them from the job of studying. However, the students reported that the multitasking was very good at meeting their emotional needs (fun/entertainment/relaxing) - interestingly, a need they weren’t even seeking to fulfill.
So multi-tasking doesn't make you more productive or help you do things better, it just makes work more enjoyable emotionally.
Totally makes sense.