What To Learn, Teach, or Research; A utilitarian approach

It's remarkable how irrationally we choose what to learn, teach, or research. We can be as simplistic as, “That seems interesting.” Or “My advisor is researching Indo-European linguistics so I'll study that.” Or “I fell into this job as a soda-flavoring taster so I might as well dig deeper.” 

We might more wisely choose what to learn, teach, or research based on just this single criterion: How likely will my focusing on this significantly improve my life and that of my sphere of influence?

My PsychologyToday.com article today offers a look at three diverse examples.