Extremely easy-to-amuse live studio audience

I watch this show most of the time on ITV3 repeats, and there is one thing I've noticed throughout the episodes: the live studio audience sound like old women in their 50s and 60s and even 70s, and they laugh at every single little things, and certain moments (that are not really funny) make them laugh so loudly and uproariously that you'd think they'd have heart attacks with the mirth. This being a sitcom from the 1960s and early 1970s, you'd think these people were really extremely starved of any entertainment whatsoever, and what's more, these people will be long dead by now.

Then I listen to the studio audience for shows like Bottom, and at least that IS uproariously funny, which to be frank, I think the audience for On The Buses would be MORTIFIED and OUTRAGED by.

I guess it's what we find funny, I suppose. I bet the BBC and ITV must've had to pick their target audiences for their shows carefully, so as not to bore or offend.