One thing i have observed is that when a guy actively searches for a relationship girls only want to hookup. But when they look for a hookup girls want to take it slow and are looking for relationships

One reason for this is the approach is when a guy is looking for a girlfriend, he becomes overly romantic and even sexual, this escalates attraction quickly, causing the girl to want to sleep with him but after that she loses interest.

On the other hand when a guy looks to get laid, his approach is systematic, resulting in girls taking it slow, (eg dates).