@compmon is correct – you declare a concentration during your sophomore year. However, most liberal arts colleges will not let you declare a major in something that you haven’t already taken the intro course for. For example, you can’t say “I want to be an anthropology concentrator” without having first taken the Intro to Anthropology course. That’s true at Harvard and most liberal arts colleges – ivy and non-ivies alike. Students have all their freshman year, and some or all of their sophomore year, to explore their options by taking intro courses in subjects that interest them. Hopefully, by the end of your sophomore year you’ve narrowed your choices down and can easily declare a concentration in something you love to do. At some colleges, it’s possible to even change your major during your junior year, however doing so requires the student to take more than 4 courses a semester in order to graduate within the four-year time frame.