I've spent sometime studying this. I personally believe Lumosity and the like are a waste of time (if not a downright scam) and do not make anyone smarter. Until I see scientific data that proves otherwise this will remain my belief. However that doesn't mean I don't believe in brain training
By your definition, smart is knowledge AND the ability to draw connection between facts and ideas. And although solving simple puzzles may not train you for the latter, continuously solving mathematical problems (that may otherwise not have any real world applications) will train your brain to find patterns.
If someone can make Calculus, Graph Theory and Discrete Mathematics fun enough for people to tackle daily, you'll have a real brain exercise platform.
Here [0] is an interesting article that talks about both sides of this argument. It has examples of studies that have shown real life advantages to these types of brain training. Some examples include increased scores on standardized tests in teenagers and better memory recall in adults 65+
I like the analogy that the brain is a muscle and if you don't exercise it, parts of it start to atrophy.
I think these brain games actually bring a lot of value to people who have retired and are no longer required to exercise their brains in order to fulfill their basic requirements of life.
Maybe they don't make you smarter, but perhaps they help prevent you from getting stupid.
By your definition, smart is knowledge AND the ability to draw connection between facts and ideas. And although solving simple puzzles may not train you for the latter, continuously solving mathematical problems (that may otherwise not have any real world applications) will train your brain to find patterns.
If someone can make Calculus, Graph Theory and Discrete Mathematics fun enough for people to tackle daily, you'll have a real brain exercise platform.