It depends on what area(s) of intellectual property law you want practice. Trademark and copyright law really wont benefit much from any specific undergraduate major. Patent law practice would benefit from an undergraduate degree in sciences like engineering or chemistry and in general if you want to go into patent prosecution (applying for and receiving patents on behalf of clients) you have to have an undergraduate degree majoring in sciences or the equivalent coursework in the sciences.
Whatever major you choose, you also want to take courses that will maintain or develop strong writing and analytical skills such as courses in political science, philosophy, literature, and history. If you choose to major in a science to cover your bases for patent law, you may want to consider taking a minor in one of those areas of study to round out your resume and skillset.
The California "palimony" case Marvin v. Marvin is a pretty famous case on family law. You can find an overview below.