If you don't care about a bunch of theory and just want to play some games, or if you don't care about "training your intelligence" but you could go for a couple cool puzzle games, go ahead and scroll down a few paragraphs.
So I've been developing my own theory on intelligence, what it is and how it works and so on, and I decided to put together an "Intelligence Trainer" program based off of my ideas. I won't go into extremely rigorous details of the theory here, but roughly, the part of the idea that is relevant here is that, by practicing a variety of tasks that require a certain skill, you will improve your ability to perform other tasks that require the same skill, even without direct practice on those other tasks. I think this sounds very reasonable. If you learn how to play piano songs from sheet music, then you should be able to learn how to play any song that doesn't have something new or too difficult, even when those songs aren't the ones you originally practiced. The skill you learned isn't [playing specific individual piano songs by looking at the sheet music for the song] but a broader skill of [reading sheet music to play any piano song from the sheet music]. This concept of improving something more by practicing basics and fundamentals appears all over. In sports, you do drills not so that you become good at the drill, but that you become good at a skill that applies to more areas. In school, in general you do homework not so that you learn how to answer your exact homework problems, but so you become good at solving all of the problems of those types. Now, the relationships between different tasks are not always obvious. Take Dance Dance Revolution and Beatmania, for example. One requires you to press 4 buttons with your feet, and the other requires you to press 7 buttons with your hands and turn a turntable. But, the mental process you must perform is very similar. You must read a stream of notes, interpret it as a sequence of actions to perform, and then perform those actions. The actions are different, but the mental processing is similar. (In the same way you could have some tasks that seems quite similar on the surface, but actually require very different mental processes.)
So, if you become good at a broad set of tasks by improving fundamental skills, what are the fundamental skills of intelligence? I would say memory and associations between memories. Now this is another claim that ought to be supported, but I won't go into that here either, other than saying that I believe all of human reasoning can be explained as a combination of memory and associations. So, the above would imply that you just do a bunch of different memory games and a bunch of different logic games and your intelligence should improve. "Well that sounds too simple," yes, that is too simple. Some people will improve more, and some will improve less, so what causes that difference? The answer this theory provides is: it depends on your current ability in the area in which you are trying to improve (and your ability will depend on a combination of talent and practice). Also, the extent to which the improvements will extend to other tasks will depend on the method you use to perform the task. Returning to the rhythm games examples, if you are naturally talented at rhythm games, or if you have had practice in some similar task that allows you to pick up rhythm games more easily, then you can probably play a wide variety of songs and levels and see large improvements. However, if it's something completely new and foreign to you, you probably don't want to try hard levels or a lot of different songs. You'll want to start with something basic first, and slowly build up. Next, if you were to learn a song by memorizing the specific steps to the song rather than reading the notes, well, that method would be less effective in helping you pick up other songs as opposed to learning how to read notes from playing the song (but in this case, it's much harder to memorize the steps to an entire song than it is to learn to read the notes, so most people will naturally do the second).
How does this apply to intelligence? Well, if your memory is very good, then you probably want to try a large variety of memory tasks, and do tasks that require using memory in ways that feel brand new to you, tasks that are at a difficulty level that will challenge you. If your memory isn't that good though, then you'll want to do simple memory tasks that are slightly challenging for you. This doesn't mean that variety is bad, but, you want to make reasonably large improvements in the tasks, and, even when you do, the improvements may not transfer to different tasks as quickly (as you'll have to build up lower skills first).
So, to answer the obvious question, "What makes your intelligence trainer better than, say, Luminosity, or the dual-n-back task?" I have two answers: a lot of related variety, and inductive reasoning puzzles. Each game focuses on a general concept, but builds up the complexity. The goal is to make slight adjustments to the mental process required for each task. At a very simple level, in The Shuffle you have memorizing numbers and then letters and then numbers and letters. But for most people, those will probably feel pretty similar. As you move up, you have to memorize out of order, and then memorize in order, but the order changes. To do this, you could use a similar mental approach: memorize information, and also memorize an order, just on one level the order remains constant and on another it changes. The goal is to provide enough variety in the game so that there is a lot of room to broaden your ways of thinking and memorizing without being too focused on a single task.
As for inductive reasoning, as far as I know Luminosity doesn't have any inductive reasoning tasks (but I'm not a member and haven't visited the site in a while, so I don't know). An ability to perform inductive reasoning well could be the major skill possessed by people who can think critically, solve broad problems, be creative, create new knowledge and more, but, regardless of how broad the applications may or may not be, strong inductive reasoning will always be beneficial. This game currently offers 2 inductive reasoning games, with a few others planned out but not implemented yet.
The last note is that there is still going to be a lot of value in Luminosity, and the dual-n-back, and anything else. Rather than a complete replacement to other options, you should consider it as an alternative that's also worth trying out. This alternative aims to improve over others in certain aspects and incorporate concepts that are not a part of other intelligence training tasks, but even then, you'll want to look at variety, and do a lot of new and different things.
This program is far from complete, and there are many new games that may be implemented (some fully planned out and some just concepts), as well as improvements to all of the current games that might be put in. Of the things I want to add, a long-term memory game tops the list, as there aren't any of those yet and I have a couple ideas for some. But if you're interested in trying out the current version, here it is:
https://skydrive.live.com/redir?resid=3CB0B68BD7EA7268!115&authkey=!APK5P22g58xbtJc&ithint=file%2c.zip.
If anyone's interested in a mac version, feel free to comment and I can make one.
Read on for my comments about the program.
