In addition to what people have suggested, play games. Don't play the same game over and over, but try to focus on different games, and try to be brutal on your

In addition to what people have suggested, play games. Don't play the same game over and over, but try to focus on different games, and try to be brutal on yourself by playing mindfully (thinking hard about what's the best way to do what you're trying to achieve). Once you have reached a level of competency, tear yourself away from the game and pick a new one to master (this is surprisingly difficult). Board games, word games, video games, outdoor games, anything and everything. Try to mix those categories, and mix genres as well as you play (puzzle video games are an exception, have at as many of those in a row as long as they aren't clones, because they have enough variety among themselves). My understanding is that intelligence is basically the speed and accuracy at which we are able to assess and model a situation and arrive at approaches to solve the problems that are presented. Like all other things, it's a question of being comfortable and getting used to being in situations you haven't been in before to get faster at assessing new ones. In real life, one situation is rarely radically different from the last or next, and so our intelligence isn't exercised as much. On the other hand, games present a vast variety of circumstances, that if picked from the right pool, are completely different from each other and from what you may have experienced in real life, getting you more comfortable with dealing with fresh situations in a very low-pressure, low-stakes environment. The experience carries over to real life even when the stakes and pressure are higher. Playing games is also a great stress reliever, and if you aren't getting addicted to a single game, it's unlikely to disrupt your lifestyle in any notable way, it may just eat into a bar night (which does nothing good for your intelligence) a week :)