This question often pops up in my mind and I’d like to share my thoughts.
I think one thing is observation. We need to spend enough time with our kids to get to know them in order to identify. Exposing them to a wide variety of activities helps us identify. E.g what kind of activities do they like and willing to spend hours working on them tirelessly?
You may observe that your child has a natural acumen towards something. Of course, it is another to have passion in it. Personally though, I feel kids usually gear towards something they have natural acumen in, because they tend to pick it up faster than their peers, and perform better in that area than their peers, which make them feel encouraged and more confident. Whether this develops into passion or not, I feel, also depends very much on the encouragement he receives and opportunities.
If a child is good at visual arts and creative thinking, but parents do not see value in it or could not recognize the gift and forces him to do something else, then the child does not receive the encouragement that is necessary for the gift to develop into a passion. As for opportunity, it is the time available for pursuing it (e.g. if need to do lots of tuition, then of course no time for creating anything, and insufficient time given to child to realize his creativity). Environment which allow such pursuits to develop is also a key factor (e.g. some schools place little value in arts/music lessons that although they are scheduled for such classes, they are taken over by Math / Science remedial).
On the other hand, a child who has passion in doing something may not necessarily have natural acumen in that area. However, because of encouragement and the opportunities available, and most importantly, his willingness to spend long hours working on it, his personal drive may develop into something exceptional.
Generally, I find this is what our school education system is lacking – an environment to encourage our children to experience doing different things (too much emphasis in academics). Since much time is spent in school, diverse opportunities should be created to allow students to flourish in areas they are good at rather than drilling them in doing well in specific subjects. This will help children in identifying their strengths and passion for later pursuits in life.
Meanwhile, as parents if we are willing to put less emphasis in academics, I find school holidays to be a good time to identify our child’s passion, because we could enrol him in a course or give him time to work on something he’s been wanting to work on, such as a piece of art or learn to play his favourite song. Create the opportunity for the spark to lighten up into a fire.
If one does not have any passion in something, it could be that he/she has not experienced life enough – doing various things instead of sticking to routines, not identified it, or possibly, generally lacking sense of perseverance.
That said, I am still trying to identify my kids’ passion. Often, I notice that they like to do something, but lack the perseverance to complete it, or to overcome the obstacles. I find this is an area I could help them in – encouragement.