Why such an outpouring of adulation for Michael Jackson?

Admittedly, he's a talented performer, and his popularity undoubtedly stems from his abilities as a singer, songwriter, dancer and performer. But as with every entertainer of such mass appeal, part of that popularity can be explained by the image and personality he projects. That image, moreover, is highly unusual and goes against many earlier rock-star stereotypes. But, in the view of many psychologists and observers, it may be the very unconventiality of Mr. Jackson's persona that makes him the star of the moment and accounts for his appeal to contemporary - especially young - audiences.

On stage, Mr. Jackson, who, with his brothers, started a multicity, multimillion dollar concert tour last Friday, is famed for his sexually ambiguous appearance and voice. In that regard, he resembles several other recent rock stars, such as David Bowie and Boy George, the latter of whom was the subject of ''Androgyny,'' a program on ''Face the Nation'' on CBS yesterday. Lives as a Virtual Recluse

But in the view many psychologists, Mr. Jackson's appeal may go beyond androgyny. In his private life, according to portrayals in the popular press, Mr. Jackson, who is 25 years old, has never touched alcohol or drugs, eats no red meat and is a virgin. A devout Jehovah's Witness, he lives with his parents as a virtual recluse, although he occasionally makes forays in disguise to distribute religious literature.

Mr. Jackson reportedly spends much of his free time watching cartoons from his own large collection, carries on imagined conversations with mannequins as though they were people, and has very few personal friends. One of those friends, Jane Fonda, has said: ''Michael reminds me of the walking wounded. He's an extremely fragile person.''