Human beings have an obsessive desire to remain consistent. It is psychologically impossible to dislike the person who has already made you laugh genuinely for more than 5 times, because humans can’t handle the incongruity between laughter (liking someone) and disliking someone.
In other words, women tend to get closer to a guy who has consistently made them laugh! This not only occurs at a logical level (“oh, being with him gives me so much joy and I want more”), but also at a subconscious level (maintaining consistency). Once we were made laugh by someone, it would be very inconsistent if we still maintained an antagonistic attitude towards that person.