Use pavlovian conditioning to suss out who likes you.
Russian physiologist Ivan Pavlov has been associated with discovering classical, or Pavlovian, conditioning. In essence, it refers to learning via association. For instance, ringing a bell and rewarding a dog with a treat can help the dog associate the bell with rewards, just like Pavlov did.
This might help you determine whether or not someone likes you. Whenever they say or do something, give them a smile or a complement. They will subconsciously begin saying or acting in that way more frequently if they like you and genuinely desire that grin or complement.