The study finds people who have negative issues with the LGBT community have higher levels of psychoticism and immature coping mechanisms than those who are accepting homosexuality as a norm. But it does not mean homophobic people are psychotic. Psychoticism is defined as a personality trait that is prone to take risks, exhibiting anti-social behaviors, impulsiveness, or non-conformist behavior while psychotic is a condition characterized by being detached from reality.
Furthermore, people with a healthy mentality have a higher level of mature defense mechanisms and are less likely to be homophobic. A person with a mature defense knows how to regulate emotion and does not depend on others for validation, while immature defense includes impulsive actions, passive aggression, or deny a problem and blaming it to others.
Also, earlier research also found homophobic people harbor same-sex desires themselves, but some studies counter-argued that these ' kinds of species' just really despise same-sex attraction, perhaps influenced by religious beliefs, hyper-masculinity, misogyny, or sensitivity to disgust.
But the sad truth is homophobia is a culture-induced disease that religion and other "conservative" institutions that adamantly spreads.