This Fast Company article makes a great point about how multi-tasking does not necessarily make us more productive. Likely, it’s just the opposite.
Doing two things at once, like singing while you take a shower, is not the same as instant messaging while writing a research report. Don’t fool yourself into thinking you can multitask jobs that need your full attention. You’re not really having a conversation while you write; you’re shifting your attention back and forth between the two activities quickly. You’re juggling. When you juggle tasks, your work suffers AND takes longer–because switching tasks costs.