Efficient way to iterate over elements of array for matching contents of another array
Your particular example gets 10 times faster by just removing the jQuery and using a for loop and .indexOf() instead of the jQuery versions.  It's also worth stopping the iteration when you find an excluded value since you don't need to look any more once the flag is already set:

var excludeMe = ["in west", "philadelphia", "born and", "raised"];
var needsExclusions = ["philadelphia", "raised"];
var someFlag = true;

for (var i = 0; i &lt; excludeMe.length; i++) {
    if (needsExclusions.indexOf(excludeMe[i]) !== -1) {
        someFlag = false;        
        break;
    }
}


Here's a jsperf that illustrates the speed difference: http://jsperf.com/exclusion-test

If you had a much large data set, then it might pay off to put the needsExclusions values into an object to serve as a direct lookup index (faster than array.indexOf()), but that's probably only faster when the list gets a lot longer because there's setup overhead to build the initial index.