I don't think that they would add a psychology course because we don't necessarily want kids knowing much about that (psychology can be used against people). You could find some stuff on YouTube, but your best bet will be books and your teacher. 

Also, Khan Academy focuses on relevant subjects (i.e. academia, computing, economics and life skills), and psychology is not particularly relevant. 

i think Khan Academy should consider adding an AP psych course. i think psychology is pretty relevant if you think about it, the study of human behavior is pretty necessary in day to day life; the demand for therapists and other psychology related jobs are increasing. one concern could be that kids shouldn't be exposed to this information because it can be used against people; well if we look at the courses Khan Academy offers we will see courses such as  AP Physics, Macroeconomics, Calculus and a lot of pretty advanced courses. In the event that a kid comes across the AP psych course, the language and topics discussed will most likely be too complex for them to understand. Khan Academy is used by many schools nationwide from elementary to high school and maybe even amongst college students, elementary students are not likely to log onto Khan Academy and open up a random course to learn, and if they do they probably won't understand a lot of the language being used, a middle schooler might log on and learn the course if they are interested in psychology but AP psychology doesn't teach topics that would be potentially harmful such as manipulation; so even if a middle schooler does watch the course there would be no harm done. 

I would love it if Khan Academy offered an AP Psychology course! They explain things so well and have truly helped me understand things better. I'm considering taking AP Psych next year and would definitely use Khan as a supplement if they offered the help!

hey if you guys wanna upvote an ap psych request there is already one with abt 31 upvotes from 3 years ago here.
https://support.khanacademy.org/hc/en-us/community/posts/360072139392-AP-Psychology

Yo who said AP Psychology can be used against people, you gotta be silly 💀

plus won