LinkedIn had a section dedicated to listing your personal hobbies, skills, and interests on your resume, but it has since removed it. However, as part of the "Additional" category of profile sections, you can cite causes you care about, such as poverty alleviation or veteran support.
You can also now add influencers, schools, groups, and associations that reflect your professional interests. Simply use the search bar at the top of your profile to find topics, people, or groups that match your interests and hit follow to add them to the section.