I would give everything I have, including my left testicle, perhaps even my right, to have grown up in the early 70's. It was a different time for cinema, especially the horror film. Horror films are released these days, which attempt to shock us with gore and not really much else. We've all become desensitized to the emotional affect of violence, and films just aren't scary anymore; we've seen it all before. In 1974, they hadn't seen it all before, and I believe audiences were genuinely frightened and even emotionally affected by the film. I've heard many stories of people fainting during screenings, though I don't know if this is actually true.
My reasoning for stating that I believe the film 'genuinely affected people' is that the film was banned in so many countries. Banned in the United Kingdom until 1999; banned in Australia until 1984. All this after director Tobe Hooper had hoped to get a PG-13 rating. The film realistically could receive a PG-13 rating if it weren't so intense, as the violence isn't explicit and there's virtually no gore. The violence, while it most certainly occurs, is implied rather than displayed. When a woman is hung on a meathook, there's no penetration of the skin, and no blood. Any violence you think you saw is all in your head. So, a movie with no blood or visibly depicted violence draws an uproar for being too horrific... that is a perfect example of a film affecting its audience.
Hooper's minimalist approach is what makes the film so effective. Shot on 16mm film for somewhere in the neighborhood of $140,000, "Texas Chain Saw" has a very gritty, very real feel to it. Its an excellent representation of budgetary limitations working in the films favor if the film is the work of a capable director, which Tobe Hooper most certainly is. It's not a pretty film to look at, but that only serves to increase the films effectiveness, as it feels less like a film than it does a genuine occurrence.
Speaking of 'genuine occurrence', "Texas Chain Saw"'s opening narration (voiced by a young John Larroquette) claims the film to be based on a actual events. This is not true, though I believed it was for many years when I was just a young kid. The film is in fact inspired by numerous sources, including the story of well-known psychopath Ed Gein, who's life was also a source of inspiration for "Silence of the Lambs" and "Psycho", however Hooper's film is more directly inspired by that particular source.
I think another big reason the film had such an impact on its initial audiences was that the characters were the perfect compliment to the ultra-realistic appearance of the film. The villains were real people; demented, but real. They had no supernatural powers and they were limited to the same boundaries that we are, yet they were still very frightening. Leatherface is an icon of the genre, but a more understated, yet even more terrifying character is that of Edwin Neal's “Hitchhiker”. The scene in which the kids pick him up is truly one of the most uncomfortable horror movie moments I've ever witnessed, made all the more effective through the collaboration of a realistic film making technique and a terrifyingly real character.
"The Texas Chain Saw Massacre" is the quintessential horror film from the 1970s. Not only is it one of the most influential horror films ever produced, but it was a turning point in the genre that ultimately redefined what horror cinema was capable of. Those who've never seen it will most likely find it quite tame by today's standards, yet its influence is undeniable. The film is evidence of the strength of proper restraint, and proof that our growing dependence on film makers to constantly 'up the ante' in terms of shock effects and violence, is only the beginning of the decline of the modern horror film.