BLAME IT ON the book reviews. Blame it on the fact that at the bottom of the reviews, down where you are told a thing or two about the reviewer, it sometimes says that so-and-so is an observer of the American scene. Nothing more. Not whether. Not whether so-and-so has a paying job or regular hours or anything like that . . . No matter, I decided to become an observer of the American scene.

That is why I am writing about Farrah Fawcett-Majors. She has become something of an obsession with me. Everyone says, in the jargon of the times, that she is "about" something. Some people have told me that she is about America: others say she is merely about California, and some hold that she is about teeth or health or hair or athletics or even, as some columnist wrote recently, about hyphenated names - confusing, I think women with brokerage firms.

The point, though, is that she clearly is about something, although for the life of me I can't figure what that might be. You have only to read the statistics to see is the personification of something. Her poster sells in the billions, her dolls are hot items in toy stores, and she is on the cover of every magazine, save possibly Popular Mechanics and Consumer Reports. People keep asking me to write something about her - say what she is about.

So one day last month, I simply went down to the Safeway and brought every magazine with Farrah Fawcett-Majors on the cover. There were eight in all, and most of them were movie type magazines, the kind that promise a lot in the headlines but deliver next to nothing in the stories. There were stories galore about Fawcett-Majors and the Mister Majors, as my grandmother would have called him, and it seems that they are getting among either swimmingly (McCall's) or not at all.But the headline that caught my eye was from McCall's cover. It was a quote from herself saying, "I'm no Marilyn Monroe." I beg to differ.

What I mean is that I never understood the Marilyn Monroe craze, either. I never found her interesting - sexy, in a n obvious sort of way, but not interesting. That was, of course, before we knew about the pills and the problems and the marriages and the Actors Studio and all the angst, all that interesting angst. Back when she was a craze, though, she was always coming on as a dumb blonde, and there is nothing to me sexy about dumbness. There is after life a special time and , if I was going to spend it with anyone from the silver screen, I would much prefer, say, Kate Hepburn or Lauren Bacall to Marilyn Monroe.

I have somewhat the same feeling about Farrah Fawcett-Majors. Her appeal eludes me. I don't find her activities or, to put it another way, I don't find her any more attractive than a lot of the California scenery you see on television. Yet it is clear that I am in the minority and that she is, as everyone says, about something - maybe America. I don't doubt it.

I've had my theories. At first I thought she wasn't about sex at all. I thought she was too clean and wholesome and athletic to be seen as a sex object. I mean, who's got that kind of wind? So I went around and asked men, and I found out thant with one exception, she was considered sexy. Even my friend, Kenny, a cynic if there ever was one, said be found her sexy. I was alone.

Then I watched the television show. On that particular night, the young women in the employ of this Charlie character were involved in some athletics having to do with a prostitution ring and a corrupt cop with greasy hair and shifty eyes. Had the girls stopped running for a minute and looked at their man, thye would have spotted him for the culprit he was. But the women never caught on and, indeed, almost were dispatched to angel heaven (a bit redundant, no?) in an auto junkyard. I summarize, because I paid little attention to the plot and lots to Fawcett-Majors, waiting for her to work her magic on me. Nothing happened. In fact, if I made any discovery at all, it was that she is a bit on the skinny side and probably not a good eater.

I thought about that and then I thought that she probably was about skinniness and the whole dieting fad - liquid protein and fasting and all that. And then I imagined her on the Johnny Carson show, Johnny thumping his pencil on his desk, and Farrah saying she was going to star in the Mahatma Gandhi Story and the audience just going wild, Johnny going thump, thump, and Alan King at the other end of the couch saying he was going to open at the Sands Hotel in September.

Anyway, I kept at it. I went to a toy store, and I looked at the Farrah Fawcett-Majors doll. NOthing. No insight. I talked to people. I read all the magazines stories. I trotted out theories. I brought her name up whenever I could. People always seemed interested, and then they would have little to say, or if they did have something to say they would say that men found her sexy and women found her not threatening and that she was either about women's lib or a reaction to it. Take your pick.

So there I was with my credentials as an observer of the American scene on the line when I went to the newstand last week and I saw that two tabloids - the National Star and Modern People - had pictures of Kate Jackson on the cover. And then I thought maybe it was the beginning of the end of Farrah Fawcett-Majors and I thought she was maybe beginning to slip and I would no longer have towonder about her.

Now I found her interesting.