Joining a society or association is a great way to become involved in your profession. Many societies offer discounted membership pricing for college students. Participating in a society allows networking, leadership, and scholarship opportunities. Many societies also maintain a list of job postings, which are a good idea to read while in college. Reading job postings helps students understand what skills to focus on and develop.
There are many more psychological societies than what is listed here. There are societies for specific ethnic groups and nationalities.