Planning - Target Audience

Considering that our film opening is a mystery thriller, it'll involve peculiar events that would typically gain the curiosity for a maturer, older audience. However, we intend to contain suspense and to keep the everyone who would watch this film, cushioned on the edge of their seats.
Whilst doing research, I've found out that the target audience for a generic thriller film is a young adult demographic from 18-25. Personally, I think this film would appeal to adults, of young/middle age (18-49; no offence to those older than 49). When I asked both my parents whether or not they'd watch it, after informing them of the synopsis; they both thought it sounded interesting and that they'd watch it in the cinemas. However, none of them were prepared to say this on camera. I believe the same premiss applies with the younger audience; college peers of mine like the idea of the film and reckon, "There aren't enough like it, in today's cinema".