The word is not 'soul', its 'personality'. When we spend time with someone, we get to know them as a person, their likes, dislikes, nature, qualities. You fall in love because their nature appeals to you and you like the way they connect to you.
You can't fake for long, if you grow close to someone then you will know what kind of person they really are.
And I think you're confusing infatuation with love. If you don't know someone but only fall for their beauty then how can that be love?
i am saying this again not everyone will fall for someone's personality. Someone's falls for someone's beauty, someone falls for someone's sense of humor. Someone's sense of justice, someone's maturity, someone's sensibility. There is always something that makes you attracted toward someone. they becomes someone special in your life. That one quality which you like about someone and you drawn to them, than after that you starts to understand them. You start to noticing that what kind of that person is it. There like, dislike, nature and quality. Sometime that drawn quality is not enough for falling in love sometime your feeling get deeper and deeper. You couldn't control your emotion anymore. Just because that drawn quality is beauty that doesn't make your love cheap and shallow 😃