Child page automatically inherits parent template

Hi

I have a button in my top nav for about – when a user visits that page they see a sub menu displaying only child pages of the parent page.

About
– Deliveries
– Contact
etc.

Every time I create a new child page of ABOUT I have to tell wordpress (in the attributes panel) to use a specific template. eg – ABOUT

Is it possible to get a child page to inherit it’s parents template without having to select it in the admin.

Thanks
H