In one sentence, describe what the following article is about:

People used to believe intelligence was fixed, and could not be improved through effort. Contemporary evidence, however, suggests this may not be the case; while an unintelligent person may never become a genius, it seems increasingly possible that anyone has the ability to strengthen her intellect to some degree. The process is not as simple as just learning some new vocabulary words, though. It takes time and effort to learn how to engage more deeply and critically with the world around you. People learn most effectively when they are passionate about their subject matter. If you are passionate about something, you are bound to want to understand it more deeply; it is this kind of focused, sustained investigation that leads to increased intellect. True intelligence involves deep mastery of a few subjects, rather than a shallow understanding of a broad range of them. Was Albert Einstein equally gifted in physics, anthropology, linguistics, geology, animal behavior, and literary criticism? Of course not. To be a proverbial jack-of-all-trades is to be a master of none; if you try to learn a little bit of everything, you may wind up understanding a whole lot of nothing. If you're not struggling, you're not pushing yourself. Learning shouldn't be torture. It should be rewarding, though, and it probably won't be if it doesn't require much effort. Push yourself to master new ideas and enter unfamiliar intellectual territory. This is called "metacognition," and it is something intelligent people excel at. Metacognition allows you to understand how you learn, and to apply those strategies from one context to another. If you realize you learn most effectively when you study on your own, for example, you will know not to join a study group in preparation for a final exam. People sometimes forget that the brain is a physical organ like any other. Just as you skin is healthier if you bathe and your lungs are healthier if you don't smoke, a physically well-cared-for brain functions at a higher level than a neglected one. It may surprise you how much more effectively you process information if you get enough sleep and exercise, and eat plenty of fruits and vegetables. This will force your brain to negotiate new ways of constructing meaning, and increase your intuitive and conscious understanding of language systems. Thinking more about language also has the added benefit of improving your facility with your first language, and learning all those new words will help improve your memory. This exercises parts of your brain used for many kinds of cognitive processing, and introduces you to new ways of receiving and communicating information. It also helps improve your memory, and reduces stress, which can play a major factor in inhibiting intellectual growth. While keeping up with current events may not exactly increase your intellectual capacity, a truly intelligent, curious person should want to engage with the world she lives in. Having new ideas often involves building on existing ones, so it is always wise to understand as much as you can about the problems the world faces, and the ways people are trying to solve them. Remember, all news sources have a bias of some sort; make sure you get your news from a variety of sources, and never accept something as absolute truth just because it is in the newspaper. The ease with which we can obtain information today makes our lives much more convenient, but it can also make us more stupid. The neural pathways involved in reading maps, for example, are probably much weaker in Millennials' brains than in the brains of their parents. This is because most Millennials rely heavily on GPS navigation to help them find their way, while older generations had to get out an atlas if they got lost. In the same vein, if they can't remember what a word means, many people are more likely to quickly Google it than they are to sit down and focus on trying to remember. Instead of strengthening their ability to recall information, they can effortlessly obtain the information with almost no thought. Try to rely on your phone less, and your brain more. Don't write off new ideas because they are scary, different, confusing, or threaten the way you are used to thinking about the world - this natural hesitation of the human mind to hold two opposing views at the same time is called 'Cognitive Dissonance'. Be open to having your perspective changed. The ability to admit when you have been wrong is a hallmark of a great mind. Curiosity is not the same as ignorance; truly intelligent people are constantly asking questions. This is because a wise woman knows that she does not know everything. When you start learning a new skill, you will not be very good at it. That's natural. If you do something you're bad at enough times, however, you'll eventually start to be good at it. Embrace the gaps in your knowledge as portals to discovery and growth.
Dedicate yourself to becoming a lifelong learner. Follow your passions. Challenge yourself. Think about how you think. Take care of your body. Learn a language. Learn to play a musical instrument. Read the news. Rely less on technology. Be open-minded. Be okay with looking stupid.