[header] How to find out if he likes you [title] Know how physical attraction works. [step] Your brain chemistry is responsible for who and what you're attracted to. In fact, according to experts, physical attraction works a lot like addiction: both stimulate brain chemicals like dopamine and oxytocin. 
Even if he's not into you, it doesn't mean there's anything wrong with you: it's all down to the chemicals. [substeps] Research suggests that our brains can tell within one second whether we're physically attracted to someone or not.