I m in Cog psyc and not social psyc but it is very true. It is best to use your connections (or your recommenders' connections) when applying for positions. However, there is one RA in my lab who didnt have any prior connection to my PI. So it is not impossible... Just keep on looking.. You can even go to individual school's HR page to see if there are any openings.. Or of course you can email PIs directly. If you can't find any paid positions, go with unpaid position... it will be helpful in the future..
Good luck!