Convergent thinking is what we learn in school when we are paying attention. It allows us to solve hard problems with one right answer.
Divergent thinking is what happens when we stop paying attention and start doodling. Divergent thinking produces many answers, none of which are technically correct but some of which are potentially groundbreaking.
It is hard to do divergent thinking when assembling a piece of IKEA furniture. Although many of us still end up with a few extra screws.
In contrast, playing legos activates divergent thinking, especially if not trying to replicate the picture on the box.
During most of our education years, we train in convergent thinking by solving problems that have already been solved. This type of thinking is important in making sure things continue working in our society as they have been built.
For example, the immediate precursor to the IQ test was developed by Alfred Binet. It tested convergent thinking with questions like: unwrapping candy, compare two weights, vocabulary, repetition of sentences etc. (see Runco 2014)
By contrast, divergent thinking is typically something we learn outside of school while playing games with our friends or making art or music in our room. We typically don’t value divergent thinking early on, and only once someone is at a level of Picasso, does the society put a lot of value on its output.
Things like imagination, creativity, and innovation - are experienced by the divergent mind. Yet as quants, we rarely spend time on divergent activity. Yes this is the dimension of fresh ideas (for example, see Jason Voss’ CFA piece). This is also the place where great questions come from. The best way to start is with a white piece of paper and a pen (see more here, here and here).