How can I select an element which does not contain a certain child element?

$(':not(.test:has(.example))').css('color', 'red');​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

http://jsfiddle.net/9fkz7y1g/

jQuery contains():

jQuery.contains(document.documentElement, document.body); // true
jQuery.contains(document.body, document.documentElement); // false

$('.test:not(:has(.example))')

-or-

$('.test').not(':has(.example)')

Possibly

$('.test').filter(function() { return !$(this).children('.example').length; });

This filters out any elements that have any child that matches .example. If you want to filter based on descendants (not just children) that you can substitute .find for .children.