“If you have reasons to love someone, you don’t love them.”
Slavoj Žižek.
I believe there is some truth here, however, love is not an instinct.
From Wikipedia:
"Slavoj Žižek born 21 March 1949 is a Slovenian continental philosopher. He is a senior researcher at the Institute for Sociology and Philosophy at the University of Ljubljana, Global Distinguished Professor of German at New York University, and international director of the Birkbeck Institute for the Humanities of the University of London. He works in subjects including continental philosophy, political theory, cultural studies, psychoanalysis, film criticism, Marxism, Hegelianism and theology".